Source: UNIVERSITY OF NEBRASKA submitted to
DEVELOPING THE TOOLS AND GERMPLASM FOR HYBRID WHEAT
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1011220
Grant No.
2017-67007-25931
Project No.
NEB-22-386
Proposal No.
2016-06703
Multistate No.
(N/A)
Program Code
A1142
Project Start Date
Dec 15, 2016
Project End Date
Dec 14, 2020
Grant Year
2019
Project Director
Baenziger, P.
Recipient Organization
UNIVERSITY OF NEBRASKA
(N/A)
LINCOLN,NE 68583
Performing Department
Agronomy & Horticulture
Non Technical Summary
The long-term goal of this project is to develop the necessary knowledge base, germplasm, and heterotic pools to support the development of hybrid wheat. Wheat (Triticum spp.) yields will need to increase by 1.7% per year (from its current increase of 0.9% per year) to feed a larger global population with increasing dietary needs. Hybrid wheat, which is more climate resilient than pureline wheat, can contribute to achieving this goal. The project objectives are to: (1) screen two large wheat breeding programs for the floral and plant traits needed for efficient hybrid seed production and hybrid performance; (2) create and test hybrids to establish and confirm heterotic pools in wheat; (3) genotype the lines going into the heterotic pools and improve algorithms to separate lines into maximum likelihood pools for future testing and validation; and (4) map restorer genes in T. timopheevi cytoplasm and create a series of cytoplasmic male sterility (CMS) tester lines, their maintainer lines, and a series of elite restorer lines (R-lines) and begin to determine the efficacy of CMS-based hybrid systems. The project team has made great strides in the U.S. and abroad toward developing the tools to foster hybrid wheat development to maximize wheat yield potential. Using an integrated approach involving in-house germplasm, chemical hybridizing agents, breeding, phenotyping, genomic selection, and quantitative trait loci mapping, this project is expected to help create the scientific and germplasm foundations for successfully launching the hybrid wheat industry in the U.S. and is thus relevant to the NIFA-IWYP program.
Animal Health Component
0%
Research Effort Categories
Basic
10%
Applied
85%
Developmental
5%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2011540108175%
2021544108110%
2021540108015%
Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms; 202 - Plant Genetic Resources;

Subject Of Investigation
1540 - Hard red winter wheat; 1544 - Hard white wheat;

Field Of Science
1081 - Breeding; 1080 - Genetics;
Goals / Objectives
The need for increased cereal production is clear as we must feed an ever larger global population with greater dietary needs (Whitford et al., 2013). To meet these needs, it is estimated that wheat (Triticum spp.) yields will need to increase by 1.7% per year; however, current wheat production trends are increasing by only 0.9% per year. In contrast, the much better resourced crop maize (Zea mays L.) has a current yield increase of 1.6% per year. One reason for this trend is that maize is largely a hybrid crop which exhibits substantial heterosis (i.e., hybrid vigor) compared to traditionally self-pollinated crops. In other words, hybrid wheat has the potential to greatly improve the yield per year increase if adequate heterosis can be developed and if practical mechanisms of producing hybrid seed can be implemented.With regard to yield, hybrids like maize have the advantage over traditional crops in that either hybrid parent can be a source of disease or pest resistance, and when the resistance gene is dominant, parents can impart this trait to the hybrid progeny. Seed would be purchased annually, thus providing the resources to support a robust crop improvement program similar to that of maize. Increased grain yields (i.e., through a second Green Revolution) are also needed to preserve land for other uses (Stevenson et al., 2013).The development of commercially successful wheat hybrids first requires cost-effective methods of creating hybrids, sufficient levels of heterosis to make purchasing hybrid seed economically viable, and a suite of methodologies to create and improve heterotic pools using innovative current and forthcoming technologies. With the pressing need to improve wheat (T. aestivum L.) productivity, our long-term goal is to develop the necessary knowledge base, germplasm, and heterotic pools to support the development of hybrid wheat. Toward that end, the objectives of this project are to:Screen two large wheat breeding programs for the floral and plant traits needed for efficient hybrid seed production and performance;Create and test hybrids to establish and confirm initial heterotic pools in wheat;Genotype the lines going into the heterotic pools and improve algorithms to separate lines into maximum likelihood pools for future testing and validation;Map restorer genes in T. timopheevi cytoplasm and create a series of CMS tester lines, their maintainer lines, and a series of elite restorer lines (R-lines) and begin to determine the efficacy of CMS-based hybrid systems.Bringing together an international team of researchers from the University of Nebraska-Lincoln (UNL), the International Maize and Wheat Improvement Center (CIMMYT), Texas A&M University (TAMU), the University of Hohenheim, Kansas State University, Genetics and Crop Plant Research (IPK), and a number of consultants, the proposed project builds on our team's vast experience in highly successful and diverse cultivar breeding efforts and is well poised to develop the necessary publically available knowledge base and germplasm to support the successful development of hybrid wheat (see "Biographical Sketches" and "Key Personnel Roles" for additional details).
Project Methods
Objective 1. We will continue to screen over 350 new lines each year in Nebraska for anther extrusion. We will confirm previous anther extrusion on 150 elite lines each year. A similar set of new TAMU lines will also be screened in Texas. Planted in fall 2015 for evaluation in spring 2016 were the 299 lines in the Hard Winter Wheat Association Mapping Panel (HWWAMP, Guttieri et al., 2015). This panel represents the historic to modern germplasm of the U.S. Great Plains and has been genotyped using the 90K SNP chip. Hence, we can map the QTLs associated with anther extrusion using pre-existing marker data. We will repeat this experiment during the 2016-2017 season. The Nebraska preliminary, advanced and most of the elite yield trials lines are genotyped using genotype-by-sequencing (GBS), and genome-wide association mapping (GWAS) will be used to identify QTLs for anther extrusion (AE) in our breeding programs. We performed preliminary GWAS analysis on 184 lines and found 9 SNP markers (with P<0.001) that were placed above majority of the SNPs in the Manhattan plots. There were no associations that passed the Bonferroni statistical significance threshold (P<0.05). The 9 SNP markers were located on 1BL, 3B, 5BL, 6AS and 7BS chromosomes. Skinnes et al. (2010) identified 4 QTLs for anther extrusion in a hexaploid wheat biparental mapping population on 1AL, 1BL, 4DL and 6AS. We are currently investigating whether the genomic regions on 1BL and 6AS overlapped in the two studies. To identify floral and plant traits needed for efficient hybrid seed production, we will visually score gaping after the use of a CHA and in our CMS lines.Objective 2. We have access to the Saaten-Union CHA Croisor® 100 for this project. Our goal is to produce over 600 wheat hybrids per year. Our parental lines will be from two diverse wheat breeding programs: Texas and Nebraska (Chao et al., 2011). Both sets of parent lines will be chosen based upon flowering time, genetic diversity, floral characteristics (Zhao et al., 2015b; Boeven et al., 2016), and results from our hybrid yield trials in 2016. The female parent lines will also be selected for gaping and the male lines for anther extrusion. All parents will be semi-dwarfs to avoid lodging due to heterosis for height (a conventional height parent line will lead to a hybrid that is too tall and may lodge). The lines will be tested four to seven environments. Our mating design in future will be a balanced missing design based upon Zhao et al. (2015b) where we will have 50 male lines and 100 female lines. We will have 25 crossing blocks in Texas and 25 crossing bocks in Nebraska to avoid the risk of catastrophic losses by inclement weather. Each crossing block will have one male line surrounding randomly assigned 14 female lines, with the "male" line used as a female. Females will be grown in 3 m x 1.2 m plots at twice the normal seeding rate surrounded on both sides by strips of male parents. A sample of heads from every female line from two of the male crossing blocks will be bagged to estimate the efficacy of the CHA. Using the balanced missing crossing block design, each female will be in seven or eight crossing blocks. The experimental hybrids will be evaluated in three locations in Nebraska (Lincoln, North Platte, and Alliance) and in three locations in Texas (Bushland, McGregor, and Farmersville) using 50% to 75% of the normal seeding rate based upon actual seed counts. The experimental design will be an alpha-lattice incomplete block design with repeated check cultivars and parent lines replicated twice to help estimate heterosis and spatial variation (e.g., Guttieri et al., 2015). We estimate the trials will be between 650 and 750 plots per location, depending upon the quantities of hybrid seed produced from each hybrid combination. Finally, we will add 50 lines that represent 30 to 40 elite European lines and 10 to 20 European hybrids selected by our collaborators Drs. Longin and Reif.The crossing block and hybrid evaluation trials will be repeated in 2018 and 2019. New lines will be added to replace those found to be unsuitable for use in hybrid production. Successful hybrid combinations will be remade for more advanced testing and model validation.Objective 3. Using the approach of Zhao et al. (2015b), we will genotype all our parental lines (50 male lines plus 100 female lines = 150 lines/year) using GBS (Poland et al., 2012). As we will be looking for new parent lines, we will genotype an additional 100 lines based upon floral characteristics for the next crossing block. Furthermore, to look for synergies between and link our hybrid wheat efforts and the hybrid wheat efforts ongoing in Europe, we will genotype 50 lines and hybrids selected by Drs. Longin and Reif. All of the 600-700 hybrids will be tested at four to seven locations to provide the needed phenotypic data on heterosis and other traits (see above in Objective 2). The genetic distance among the lines and the complete hybrid matrix can be predicted (11,175 hybrids for n= 150). This complete matrix will be evaluated using the annealing algorithm of Zhao et al. (2015b) to predict high yielding heterotic groups. Based upon the outcome of the heterotic group predictions, we will determine the optimum size of each heterotic group for further improvement. Historically, approximately 16 individuals per group are sufficient for long-term success (e.g., the creation of high yielding hybrids and the needed genetic variation for long-term, sustained improvement; Zhao et al., 2015b). In addition, the heterotic groups identified with CHA hybrids will be used to guide our CMS lines development in to R-line and B/A-lines.Objective 4. We will map multiple restorer genes to provide full fertility restoration in T. timopheevii-based F1 hybrids from a single source line by using high density Single Nucleotide Polymorphism (SNP) markers. To map the restorer genes, R38568G (an excellent restorer lines from Australia) will be crossed with a CIMMYT A-Line "Navojoa-A," which is a complete male sterile line carrying T. timopheevii cytoplasm. The self-pollination in F1 fertile plants will be confirmed by bagging each heads before flowering. A set of 300 F2 seeds will be space-planted in the field for phenotypic and genotypic analysis. Male fertility in each F2 plants will be assessed during flowering and maturity. To prevent contaminant outcrossing, similar to F1, the heads of individual F2 plants will be covered with glassine pollen-impermeable bags before flowering. At flowering, the anthers in the florets in each head will be visually evaluated as fertile or sterile. To confirm anther fertility, four random samples of pollen from each fertile- and sterile-type anther will be collected and analyzed under a microscope after smearing it with 1% iodine-potassium iodide (I-KI) solution (Sinha et al., 2013). For maker analysis, a leaf sample from each F2 plant will be collected and the DNA from each sample will be used for 90K SNP genotyping. The polymorphic and curated SNP data will be used for linkage map construction and QTL mapping analysis for fertility restoration in the F2 population. Once the linked flanking markers are identified, the SNP sequence will be used to develop breeder-friendly, allele-specific PCR assays (e.g., KASPar).The relevant experimental designs, data analyses and interpretations have been described in each objective. We will use SAS, R, and ASREML for our phenotypic and genomic data analyses. We will collaborate with Drs. Longin and Reif using their annealing and other algorithms related to the development and prediction of heterotic pools (e.g. Zhao et al.; 2013, 2015a,b; Boeven et al., 2016).

Progress 12/15/16 to 12/14/20

Outputs
Target Audience:The target audience will be small grains producers and their value chain from seed dealers to grain buyers,millers/maltsters/livestock producers, bakers and brewers, and consumers. While consumers are sometimes overlooked,they are the main determinant in our freedom to access new technologies, hence are critically important in understanding thevalue and safety of the research that is undertaken, especially hybrid wheat research. Our scientific target audience will be plant and animal breeders, geneticists, and genomicists, crop physiologists and production specialists, plant pathologists, entomologists, cereal chemists and applied statisticians. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three graduate student successfully completed their M.S. (Ms. Hannah Stoll) and Ph.D. degrees (Dr. Nicholas Garst and Dr. Anil Adhikari) in late 2019 or 2020. Dr. Amanda Easterly successfullly completed her Ph.D. earlier in the project. In addition, other students learned about hybrid wheat by helping with the extensive note taking, seed preparation, planting and harvest. All of the students were able to attend the international Crop Science Socitety of America annual meeting, our hybrid wheat work and planning meetings, and depending upon their career interests attended teaching workshops. How have the results been disseminated to communities of interest?In preparation for the launch of hybrid wheat, talks were given to the Nebraska Crop Improvement Association (80 seed dealers in attendance) and at three seed days in western Nebraska. Similar presentations were made to seed dealers in Texas. In addition, Vikas Belamkar presented a talk on behalf of the project at the Plant and Animal Genome meeting and multiple presentations were made at the annual meeting of the Crop Science Society of America. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Ourlong-term goalis to develop the necessary knowledge base, germplasm, and heterotic pools to support the development of hybrid wheat (T. aestivumL.). 2020 was a difficult year to do research as we had to work under covid-19 restrictions (greenhouse and driving restrictions). Objective 1. We continued to screen the Nebraska and Texas wheat breeding programs for anther extrusion (a male trait). In Nebraska we screened the preliminary yield trial (270 experimental lines grown in an augmented design), and the regional performance nurseries (~90 experimental lines from across the region) and a doubled haploid population (Freeman [excellent anther extrusion] x Camelot [very poor anther extrusion]) to further understand the genetics of anther extrusion. Dr. Nicholas Garst using the Hard Winter Wheat Association Mapping Panel (HWWAMP) found significant genotypic variation for anther extrusion, anthesis date, and plant height while pollination duration only had significant genotypic differences in seasons with mild temperatures. The best pollinators tended to be early and short statured (contrary to previous research that tall wheats were better pollinators). Our molecular analyses revealed a novel haplotype on chromosome 2A which separated the highest and lowest scoring lines for anther extrusion and would be a target for gene pyramiding. PPD-D1a had the largest effect on anthesis date accounting for 20% of the total variation while also being significantly associated with plant height. Rht-B1 and Rht-D1 were most important loci for plant height accounting for 17% of the total variation. No significant markers were identified for pollination duration. Hybrid breeders working to improve outcrossing should incorporate the novel haplotype for increased anther extrusion, pair parents based on photoperiod sensitivity and reduced height genes, and select environments with low heat stress for hybrid seed production. The best indicators of female receptivity appeared to be gape angle and 100% gape date (when all the spikes are fully gaping). Both female traits can be visually scored quickly and accurately. Other traits that were scored were duration of gaping, stigma exsertion, and gape closure. The female traits were highly correlated, so one or at most two could be used to select excellent female lines. Preliminary genome-wide analysis conducted with ~90 lines indicated that the genetics of key female traits may be controlled by a few large effect loci unlike male traits that seemed to be controlled by many loci of smaller effects. Objective 2: We continued to use Croisor® 100 to make hybrids. We continue analyzing the data, removing the spatial variation, comparing reciprocal crosses, and estimating heritability and heterosis from our 25 x 26 crossing block with the emphasis on determining the genetics of heterosis. We successfully used the balanced missing design pioneered by our German cooperators for the 2017, 2018 and repeated it in 2019 crossing blocks. In this crossing block, we had 50 males and 100 females (total of 150 lines with 25 males and 50 females selected by both UNL and TAMU) where each male was crossed to 14 females. To ensure that environmental hazards did not destroy the crossing block, we grew two crossing blocks (1 in NE and 1 in TX). Based upon the data from the previous hybrid yield trials, we selected the best hybrids in NE and ecological regions in TX (Blacklands and Bushland). These selected hybrids were then grown in a 3-replicate alpha lattice trial at 3 locations in NE, 2 locations in Blacklands, and 1 location in Bushland to confirm our previous data. The selected hybrids were largely different in each testing zone (NE, Blacklands, and Bushland) except for ~5 to 7 hybrids that yielded well in both states. As expected, using a replicated alpha lattice design was far more precise than our large augmented incomplete block designs with broad-sense heritability (H2) increasing from ~0.3-0.4 to >0.75. We lost one location in Blacklands and the other location also had lower heritability due to an environmental catastrophe in 2020. Preliminary results indicate highest reproducibility of high yielding hybrids in Bushland, and varying results observed in NE. To determine the effect of the Croisor® 100 on female seed set, we sprayed cytoplasmic male sterile (CMS) lines with Croisor® 100 and found the seed set on the Croisor® 100 sprayed CMS lines to be between 25 and 75% of the unsprayed CMS lines. The comparison is biased as we discovered some fertile males were contaminating the CMS lines (mechanical mixtures from the previous harvest hence the unsprayed CMS yield would be inflated). Also, Croisor® 100 delays gaping, so a Croisor® 100 sprayed CMS female will delayed and may have less chance to be pollinated. However, it does give an indication of the injury caused by Croisor® 100. This injury can be reduced with better adjuvants and application technology that is tailored to each female line as is done in commercial practice in Europe. Objective 3: All of the parental line have been genotyped, and the genomic and phenotypic analyses were completed to be point where we can predict using our hybrid yield data from 2018, 2019, and 2020 which hybrids should be made to obtain the highest levels of heterosis. The accuracy of predicting the yield of hybrids was higher in TX compared to NE locations. The high spatial-variation and low heritability values of large augmented trials in NE influenced the quality of the phenotype, which resulted in lower prediction accuracy in NE compared to TX environments. This also indicates an opportunity for research and integrating digital phenotyping and additional field covariates to increase the accuracy of phenotyping large trials in NE. Further, the ~750 hybrids tested at three locations in NE and TX in 2018 and 2019 were used as training sets and hybrid yield of ~11,000 hybrids was predicted for NE and two mega-environments (Blacklands and Bushland) in TX. From these predictions, the top 1,000 predicted hybrids were selected initially using yield. Subsequently, we dropped ~750 hybrids based on whether a successful hybrid could be made using male and female key parental traits (anther extrusion and gape angle) and the nick scores (difference in the anthesis date of male and female line in a cross). Subsequently, we designed and planted a crossing block in NE and TX in 2019-2020 based on the predicted hybrids we want to test in 2021-22. The crossing block in NE comprised ~210 high-yielding crosses and ~40 low-yielding crosses predicted and selected as described previously and ~60 crosses for elite hybrids. In TX, the crossing block included ~130 high-yielding and ~20 low-yielding crosses each for Blacklands and Bushland environments (~300 crosses in total). Besides making the potential high-yielding hybrids that were previously not made, this crossing block helped make hybrids to validate the genomic predictions. These hybrids made in 2020 are now being grown in 2-replicates, alpha lattice design, at three locations in NE, two locations in Blacklands, and one location (3 replicates) in Bushland. Objective 4: The evaluation of a biparental mapping population for restorer (Rf) genes was completed. While some previously known Rf genes were found, additional novel Rf genes were mapped suggesting that this population based on one of the best restorer lines in Australia was a rich source of pyramided restorer genes. Work continues to develop through crossing and evaluation, modern winter and spring wheat restorer lines and male sterile lines using the Triticum timopheevi cytoplasm. As proposed in the grant, we have begun sharing our CMS A-lines and their B-line maintainer lines, as well as, a few of the R-lines.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Belamkar, V., M. J. Guttieri, W. Hussain, D. Jarqu�n, I. S.El-basyoni, J. Poland, A. J Lorenz, P. S. Baenziger. 2018. Genomic Selection in Preliminary Yield Trials in a Winter Wheat Breeding Program. G3: Genes, Genomes, Genetics 8:2735-2747. https://doi.org/10.1534/g3.118.200415
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Screening Great Plains Winter Wheat (Triticum aestivum L.) Germplasm for Anther Extrusion and Evaluating the Effect of Anther Extrusion on Hybrid Seed Production Yields Nicholas Garst Masters Defense seminar and thesis
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Modeling Male Sterility Induced by Chemical Hybridization of Wheat (Triticum aestivum L.) Poster presented by Amanda Easterly at the Conference in Applied Statistics, Manhattan, KS, April 2017. Authors: Amanda Easterly, Nicholas Garst, Vikas Belamkar and P. Stephen Baenziger  University Nebraska-Lincoln
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hybrid Wheat for the Great Plains: Improving Yields and Water Efficiency? Poster presented by Amanda Easterly at the Daugherty Water for Food Global Institute at the University of Nebraska 2017 Annual Conference in April 2017. Authors: Amanda Easterly, Vikas Belamkar, Nick Garst, Jackie Rudd, Amir Ibrahim, Anil Adhikari, P. Stephen Baenziger.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Easterly, A. C., N. Garst, V. Belamkar, A. M. H. Ibrahim, J. C. Rudd, J.-B. Sarazin, and P. S. Baenziger. 2020. Evaluation of Hybrid Wheat (Triticum aestivum L.) Yield in Nebraska. Crop Science 60:1-13 . https://doi.org/10.1002/csc2.20019.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Easterly, A. C., W. Stroup, N. Garst, V. Belamkar, J.-B. Sarazin, T. Moittie, J.-B. Sarazin, A. M. H. Ibrahim, J. C. Rudd, E. Souza, and P. S. Baenziger. 2019. Determining the efficacy of a hybridizing agent in wheat (Triticum aestivum L) .Scientific Reports 9:1-11.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., A. M. H. Ibrahim, J. C. Rudd, P. S. Baenziger, and J.-B. Sarazin. 2020. Estimation of Heterosis and Combining Abilities of U.S. Winter Wheat Germplasm for Hybrid Development in Texas. Crop Science 60:788-803
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., A.M.H. Ibrahim, J.C. Rudd, P.S. Baenziger, A. Easterly, N. Garst, V. Belamkar, J.-B. Sarazin. 2020. Supplementing selection decisions in a hybrid wheat breeding program by using F2 yield as a proxy of F1 performance. Euphytica 216: 130. [https://doi.org/10.1007/s10681-020-02664-0]
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Baenziger, P.S., R.A. Graybosch, D.J. Rose, L. Xu, M.J. Guttieri, T. Regassa, R. N. Klein, G. R. Kruger, D. K. Santra, G. W. Hergert, S. M. Wegulo, Y. Jin, J. Kolmer, G. L. Hein, J.Bradshaw, M.-S. Chen, G. Bai, R. L. Bowden, I. El-Basyoni, and A. Lorenz. 2020. Registration of NE10589 (Husker Genetics Brand Ruth) hard red winter wheat. J. Plant Regist. 14(3): 388397. doi: 10.1002/plr2.20068.


Progress 12/15/16 to 12/07/20

Outputs
Target Audience:The target audience will be small grains producers and their value chain from seed dealers to grain buyers,millers/maltsters/livestock producers, bakers and brewers, and consumers. While consumers are sometimes overlooked,they are the main determinant in our freedom to access new technologies, hence are critically important in understanding thevalue and safety of the research that is undertaken, especially hybrid wheat research. Our scientific target audience will be plant and animal breeders, geneticists, and genomicists, crop physiologists and production specialists, plant pathologists, entomologists, cereal chemists and applied statisticians. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three graduate student successfully completed their M.S. (Ms. Hannah Stoll) and Ph.D. degrees (Dr. Nicholas Garst and Dr. Anil Adhikari) in late 2019 or 2020. Dr. Amanda Easterly successfullly completed her Ph.D. earlier in the project. In addition, other students learned about hybrid wheat by helping with the extensive note taking, seed preparation, planting and harvest. All of the students were able to attend the international Crop Science Socitety of America annual meeting, our hybrid wheat work and planning meetings, and depending upon their career interests attended teaching workshops. How have the results been disseminated to communities of interest?In preparation for the launch of hybrid wheat, talks were given to the Nebraska Crop Improvement Association (80 seed dealers in attendance) and at three seed days in western Nebraska. Similar presentations were made to seed dealers in Texas. In addition, Vikas Belamkar presented a talk on behalf of the project at the Plant and Animal Genome meeting and multiple presentations were made at the annual meeting of the Crop Science Society of America. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Ourlong-term goalis to develop the necessary knowledge base, germplasm, and heterotic pools to support the development of hybrid wheat (T. aestivumL.). 2020 was a difficult year to do research as we had to work under covid-19 restrictions (greenhouse and driving restrictions). Objective 1. We continued to screen the Nebraska and Texas wheat breeding programs for anther extrusion (a male trait). In Nebraska we screened the preliminary yield trial (270 experimental lines grown in an augmented design), and the regional performance nurseries (~90 experimental lines from across the region) and a doubled haploid population (Freeman [excellent anther extrusion] x Camelot [very poor anther extrusion]) to further understand the genetics of anther extrusion. Dr. Nicholas Garst using the Hard Winter Wheat Association Mapping Panel (HWWAMP) found significant genotypic variation for anther extrusion, anthesis date, and plant height while pollination duration only had significant genotypic differences in seasons with mild temperatures. The best pollinators tended to be early and short statured (contrary to previous research that tall wheats were better pollinators). Our molecular analyses revealed a novel haplotype on chromosome 2A which separated the highest and lowest scoring lines for anther extrusion and would be a target for gene pyramiding. PPD-D1a had the largest effect on anthesis date accounting for 20% of the total variation while also being significantly associated with plant height. Rht-B1 and Rht-D1 were most important loci for plant height accounting for 17% of the total variation. No significant markers were identified for pollination duration. Hybrid breeders working to improve outcrossing should incorporate the novel haplotype for increased anther extrusion, pair parents based on photoperiod sensitivity and reduced height genes, and select environments with low heat stress for hybrid seed production. The best indicators of female receptivity appeared to be gape angle and 100% gape date (when all the spikes are fully gaping). Both female traits can be visually scored quickly and accurately. Other traits that were scored were duration of gaping, stigma exsertion, and gape closure. The female traits were highly correlated, so one or at most two could be used to select excellent female lines. Preliminary genome-wide analysis conducted with ~90 lines indicated that the genetics of key female traits may be controlled by a few large effect loci unlike male traits that seemed to be controlled by many loci of smaller effects. Objective 2: We continued to use Croisor® 100 to make hybrids. We continue analyzing the data, removing the spatial variation, comparing reciprocal crosses, and estimating heritability and heterosis from our 25 x 26 crossing block with the emphasis on determining the genetics of heterosis. We successfully used the balanced missing design pioneered by our German cooperators for the 2017, 2018 and repeated it in 2019 crossing blocks. In this crossing block, we had 50 males and 100 females (total of 150 lines with 25 males and 50 females selected by both UNL and TAMU) where each male was crossed to 14 females. To ensure that environmental hazards did not destroy the crossing block, we grew two crossing blocks (1 in NE and 1 in TX). Based upon the data from the previous hybrid yield trials, we selected the best hybrids in NE and ecological regions in TX (Blacklands and Bushland). These selected hybrids were then grown in a 3-replicate alpha lattice trial at 3 locations in NE, 2 locations in Blacklands, and 1 location in Bushland to confirm our previous data. The selected hybrids were largely different in each testing zone (NE, Blacklands, and Bushland) except for ~5 to 7 hybrids that yielded well in both states. As expected, using a replicated alpha lattice design was far more precise than our large augmented incomplete block designs with broad-sense heritability (H2) increasing from ~0.3-0.4 to >0.75. We lost one location in Blacklands and the other location also had lower heritability due to an environmental catastrophe in 2020. Preliminary results indicate highest reproducibility of high yielding hybrids in Bushland, and varying results observed in NE. To determine the effect of the Croisor® 100 on female seed set, we sprayed cytoplasmic male sterile (CMS) lines with Croisor® 100 and found the seed set on the Croisor® 100 sprayed CMS lines to be between 25 and 75% of the unsprayed CMS lines. The comparison is biased as we discovered some fertile males were contaminating the CMS lines (mechanical mixtures from the previous harvest hence the unsprayed CMS yield would be inflated). Also, Croisor® 100 delays gaping, so a Croisor® 100 sprayed CMS female will delayed and may have less chance to be pollinated. However, it does give an indication of the injury caused by Croisor® 100. This injury can be reduced with better adjuvants and application technology that is tailored to each female line as is done in commercial practice in Europe. Objective 3: All of the parental line have been genotyped, and the genomic and phenotypic analyses were completed to be point where we can predict using our hybrid yield data from 2018, 2019, and 2020 which hybrids should be made to obtain the highest levels of heterosis. The accuracy of predicting the yield of hybrids was higher in TX compared to NE locations. The high spatial-variation and low heritability values of large augmented trials in NE influenced the quality of the phenotype, which resulted in lower prediction accuracy in NE compared to TX environments. This also indicates an opportunity for research and integrating digital phenotyping and additional field covariates to increase the accuracy of phenotyping large trials in NE. Further, the ~750 hybrids tested at three locations in NE and TX in 2018 and 2019 were used as training sets and hybrid yield of ~11,000 hybrids was predicted for NE and two mega-environments (Blacklands and Bushland) in TX. From these predictions, the top 1,000 predicted hybrids were selected initially using yield. Subsequently, we dropped ~750 hybrids based on whether a successful hybrid could be made using male and female key parental traits (anther extrusion and gape angle) and the nick scores (difference in the anthesis date of male and female line in a cross). Subsequently, we designed and planted a crossing block in NE and TX in 2019-2020 based on the predicted hybrids we want to test in 2021-22. The crossing block in NE comprised ~210 high-yielding crosses and ~40 low-yielding crosses predicted and selected as described previously and ~60 crosses for elite hybrids. In TX, the crossing block included ~130 high-yielding and ~20 low-yielding crosses each for Blacklands and Bushland environments (~300 crosses in total). Besides making the potential high-yielding hybrids that were previously not made, this crossing block helped make hybrids to validate the genomic predictions. These hybrids made in 2020 are now being grown in 2-replicates, alpha lattice design, at three locations in NE, two locations in Blacklands, and one location (3 replicates) in Bushland. Objective 4: The evaluation of a biparental mapping population for restorer (Rf) genes was completed. While some previously known Rf genes were found, additional novel Rf genes were mapped suggesting that this population based on one of the best restorer lines in Australia was a rich source of pyramided restorer genes. Work continues to develop through crossing and evaluation, modern winter and spring wheat restorer lines and male sterile lines using the Triticum timopheevi cytoplasm. As proposed in the grant, we have begun sharing our CMS A-lines and their B-line maintainer lines, as well as, a few of the R-lines.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Belamkar, V., M. J. Guttieri, W. Hussain, D. Jarqu�n, I. S.El-basyoni, J. Poland, A. J Lorenz, P. S. Baenziger. 2018. Genomic Selection in Preliminary Yield Trials in a Winter Wheat Breeding Program. G3: Genes, Genomes, Genetics 8:2735-2747. https://doi.org/10.1534/g3.118.200415
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Screening Great Plains Winter Wheat (Triticum aestivum L.) Germplasm for Anther Extrusion and Evaluating the Effect of Anther Extrusion on Hybrid Seed Production Yields Nicholas Garst Masters Defense seminar and thesis
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Modeling Male Sterility Induced by Chemical Hybridization of Wheat (Triticum aestivum L.) Poster presented by Amanda Easterly at the Conference in Applied Statistics, Manhattan, KS, April 2017. Authors: Amanda Easterly, Nicholas Garst, Vikas Belamkar and P. Stephen Baenziger  University Nebraska-Lincoln
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hybrid Wheat for the Great Plains: Improving Yields and Water Efficiency? Poster presented by Amanda Easterly at the Daugherty Water for Food Global Institute at the University of Nebraska 2017 Annual Conference in April 2017. Authors: Amanda Easterly, Vikas Belamkar, Nick Garst, Jackie Rudd, Amir Ibrahim, Anil Adhikari, P. Stephen Baenziger.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Easterly, A. C., N. Garst, V. Belamkar, A. M. H. Ibrahim, J. C. Rudd, J.-B. Sarazin, and P. S. Baenziger. 2020. Evaluation of Hybrid Wheat (Triticum aestivum L.) Yield in Nebraska. Crop Science 60:1-13 . https://doi.org/10.1002/csc2.20019.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Easterly, A. C., W. Stroup, N. Garst, V. Belamkar, J.-B. Sarazin, T. Moittie, J.-B. Sarazin, A. M. H. Ibrahim, J. C. Rudd, E. Souza, and P. S. Baenziger. 2019. Determining the efficacy of a hybridizing agent in wheat (Triticum aestivum L) .Scientific Reports 9:1-11.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., A. M. H. Ibrahim, J. C. Rudd, P. S. Baenziger, and J.-B. Sarazin. 2020. Estimation of Heterosis and Combining Abilities of U.S. Winter Wheat Germplasm for Hybrid Development in Texas. Crop Science 60:788-803
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., A.M.H. Ibrahim, J.C. Rudd, P.S. Baenziger, A. Easterly, N. Garst, V. Belamkar, J.-B. Sarazin. 2020. Supplementing selection decisions in a hybrid wheat breeding program by using F2 yield as a proxy of F1 performance. Euphytica 216: 130. [https://doi.org/10.1007/s10681-020-02664-0]
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Baenziger, P.S., R.A. Graybosch, D.J. Rose, L. Xu, M.J. Guttieri, T. Regassa, R. N. Klein, G. R. Kruger, D. K. Santra, G. W. Hergert, S. M. Wegulo, Y. Jin, J. Kolmer, G. L. Hein, J.Bradshaw, M.-S. Chen, G. Bai, R. L. Bowden, I. El-Basyoni, and A. Lorenz. 2020. Registration of NE10589 (Husker Genetics Brand Ruth) hard red winter wheat. J. Plant Regist. 14(3): 388397. doi: 10.1002/plr2.20068.


Progress 12/15/16 to 11/21/20

Outputs
Target Audience:The target audience will be small grains producers and their value chain from seed dealers to grain buyers,millers/maltsters/livestock producers, bakers and brewers, and consumers. While consumers are sometimes overlooked,they are the main determinant in our freedom to access new technologies, hence are critically important in understanding thevalue and safety of the research that is undertaken, especially hybrid wheat research. Our scientific target audience will be plant and animal breeders, geneticists, and genomicists, crop physiologists and production specialists, plant pathologists, entomologists, cereal chemists and applied statisticians. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three graduate student successfully completed their M.S. (Ms. Hannah Stoll) and Ph.D. degrees (Dr. Nicholas Garst and Dr. Anil Adhikari) in late 2019 or 2020. Dr. Amanda Easterly successfullly completed her Ph.D. earlier in the project. In addition, other students learned about hybrid wheat by helping with the extensive note taking, seed preparation, planting and harvest. All of the students were able to attend the international Crop Science Socitety of America annual meeting, our hybrid wheat work and planning meetings, and depending upon their career interests attended teaching workshops. How have the results been disseminated to communities of interest?In preparation for the launch of hybrid wheat, talks were given to the Nebraska Crop Improvement Association (80 seed dealers in attendance) and at three seed days in western Nebraska. Similar presentations were made to seed dealers in Texas. In addition, Vikas Belamkar presented a talk on behalf of the project at the Plant and Animal Genome meeting and multiple presentations were made at the annual meeting of the Crop Science Society of America. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Ourlong-term goalis to develop the necessary knowledge base, germplasm, and heterotic pools to support the development of hybrid wheat (T. aestivumL.). 2020 was a difficult year to do research as we had to work under covid-19 restrictions (greenhouse and driving restrictions). Objective 1. We continued to screen the Nebraska and Texas wheat breeding programs for anther extrusion (a male trait). In Nebraska we screened the preliminary yield trial (270 experimental lines grown in an augmented design), and the regional performance nurseries (~90 experimental lines from across the region) and a doubled haploid population (Freeman [excellent anther extrusion] x Camelot [very poor anther extrusion]) to further understand the genetics of anther extrusion. Dr. Nicholas Garst using the Hard Winter Wheat Association Mapping Panel (HWWAMP) found significant genotypic variation for anther extrusion, anthesis date, and plant height while pollination duration only had significant genotypic differences in seasons with mild temperatures. The best pollinators tended to be early and short statured (contrary to previous research that tall wheats were better pollinators). Our molecular analyses revealed a novel haplotype on chromosome 2A which separated the highest and lowest scoring lines for anther extrusion and would be a target for gene pyramiding. PPD-D1a had the largest effect on anthesis date accounting for 20% of the total variation while also being significantly associated with plant height. Rht-B1 and Rht-D1 were most important loci for plant height accounting for 17% of the total variation. No significant markers were identified for pollination duration. Hybrid breeders working to improve outcrossing should incorporate the novel haplotype for increased anther extrusion, pair parents based on photoperiod sensitivity and reduced height genes, and select environments with low heat stress for hybrid seed production. The best indicators of female receptivity appeared to be gape angle and 100% gape date (when all the spikes are fully gaping). Both female traits can be visually scored quickly and accurately. Other traits that were scored were duration of gaping, stigma exsertion, and gape closure. The female traits were highly correlated, so one or at most two could be used to select excellent female lines. Preliminary genome-wide analysis conducted with ~90 lines indicated that the genetics of key female traits may be controlled by a few large effect loci unlike male traits that seemed to be controlled by many loci of smaller effects. Objective 2: We continued to use Croisor® 100 to make hybrids. We continue analyzing the data, removing the spatial variation, comparing reciprocal crosses, and estimating heritability and heterosis from our 25 x 26 crossing block with the emphasis on determining the genetics of heterosis. We successfully used the balanced missing design pioneered by our German cooperators for the 2017, 2018 and repeated it in 2019 crossing blocks. In this crossing block, we had 50 males and 100 females (total of 150 lines with 25 males and 50 females selected by both UNL and TAMU) where each male was crossed to 14 females. To ensure that environmental hazards did not destroy the crossing block, we grew two crossing blocks (1 in NE and 1 in TX). Based upon the data from the previous hybrid yield trials, we selected the best hybrids in NE and ecological regions in TX (Blacklands and Bushland). These selected hybrids were then grown in a 3-replicate alpha lattice trial at 3 locations in NE, 2 locations in Blacklands, and 1 location in Bushland to confirm our previous data. The selected hybrids were largely different in each testing zone (NE, Blacklands, and Bushland) except for ~5 to 7 hybrids that yielded well in both states. As expected, using a replicated alpha lattice design was far more precise than our large augmented incomplete block designs with broad-sense heritability (H2) increasing from ~0.3-0.4 to >0.75. We lost one location in Blacklands and the other location also had lower heritability due to an environmental catastrophe in 2020. Preliminary results indicate highest reproducibility of high yielding hybrids in Bushland, and varying results observed in NE. To determine the effect of the Croisor® 100 on female seed set, we sprayed cytoplasmic male sterile (CMS) lines with Croisor® 100 and found the seed set on the Croisor® 100 sprayed CMS lines to be between 25 and 75% of the unsprayed CMS lines. The comparison is biased as we discovered some fertile males were contaminating the CMS lines (mechanical mixtures from the previous harvest hence the unsprayed CMS yield would be inflated). Also, Croisor® 100 delays gaping, so a Croisor® 100 sprayed CMS female will delayed and may have less chance to be pollinated. However, it does give an indication of the injury caused by Croisor® 100. This injury can be reduced with better adjuvants and application technology that is tailored to each female line as is done in commercial practice in Europe. Objective 3: All of the parental line have been genotyped, and the genomic and phenotypic analyses were completed to be point where we can predict using our hybrid yield data from 2018, 2019, and 2020 which hybrids should be made to obtain the highest levels of heterosis. The accuracy of predicting the yield of hybrids was higher in TX compared to NE locations. The high spatial-variation and low heritability values of large augmented trials in NE influenced the quality of the phenotype, which resulted in lower prediction accuracy in NE compared to TX environments. This also indicates an opportunity for research and integrating digital phenotyping and additional field covariates to increase the accuracy of phenotyping large trials in NE. Further, the ~750 hybrids tested at three locations in NE and TX in 2018 and 2019 were used as training sets and hybrid yield of ~11,000 hybrids was predicted for NE and two mega-environments (Blacklands and Bushland) in TX. From these predictions, the top 1,000 predicted hybrids were selected initially using yield. Subsequently, we dropped ~750 hybrids based on whether a successful hybrid could be made using male and female key parental traits (anther extrusion and gape angle) and the nick scores (difference in the anthesis date of male and female line in a cross). Subsequently, we designed and planted a crossing block in NE and TX in 2019-2020 based on the predicted hybrids we want to test in 2021-22. The crossing block in NE comprised ~210 high-yielding crosses and ~40 low-yielding crosses predicted and selected as described previously and ~60 crosses for elite hybrids. In TX, the crossing block included ~130 high-yielding and ~20 low-yielding crosses each for Blacklands and Bushland environments (~300 crosses in total). Besides making the potential high-yielding hybrids that were previously not made, this crossing block helped make hybrids to validate the genomic predictions. These hybrids made in 2020 are now being grown in 2-replicates, alpha lattice design, at three locations in NE, two locations in Blacklands, and one location (3 replicates) in Bushland. Objective 4: The evaluation of a biparental mapping population for restorer (Rf) genes was completed. While some previously known Rf genes were found, additional novel Rf genes were mapped suggesting that this population based on one of the best restorer lines in Australia was a rich source of pyramided restorer genes. Work continues to develop through crossing and evaluation, modern winter and spring wheat restorer lines and male sterile lines using the Triticum timopheevi cytoplasm. As proposed in the grant, we have begun sharing our CMS A-lines and their B-line maintainer lines, as well as, a few of the R-lines.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Belamkar, V., M. J. Guttieri, W. Hussain, D. Jarqu�n, I. S.El-basyoni, J. Poland, A. J Lorenz, P. S. Baenziger. 2018. Genomic Selection in Preliminary Yield Trials in a Winter Wheat Breeding Program. G3: Genes, Genomes, Genetics 8:2735-2747. https://doi.org/10.1534/g3.118.200415
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Baenziger, P.S., R.A. Graybosch, D.J. Rose, L. Xu, M.J. Guttieri, T. Regassa, R. N. Klein, G. R. Kruger, D. K. Santra, G. W. Hergert, S. M. Wegulo, Y. Jin, J. Kolmer, G. L. Hein, J.Bradshaw, M.-S. Chen, G. Bai, R. L. Bowden, I. El-Basyoni, and A. Lorenz. 2020. Registration of NE10589 (Husker Genetics Brand Ruth) hard red winter wheat. J. Plant Regist. 14(3): 388397. doi: 10.1002/plr2.20068.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Screening Great Plains Winter Wheat (Triticum aestivum L.) Germplasm for Anther Extrusion and Evaluating the Effect of Anther Extrusion on Hybrid Seed Production Yields Nicholas Garst Masters Defense seminar and thesis
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Modeling Male Sterility Induced by Chemical Hybridization of Wheat (Triticum aestivum L.) Poster presented by Amanda Easterly at the Conference in Applied Statistics, Manhattan, KS, April 2017. Authors: Amanda Easterly, Nicholas Garst, Vikas Belamkar and P. Stephen Baenziger  University Nebraska-Lincoln
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hybrid Wheat for the Great Plains: Improving Yields and Water Efficiency? Poster presented by Amanda Easterly at the Daugherty Water for Food Global Institute at the University of Nebraska 2017 Annual Conference in April 2017. Authors: Amanda Easterly, Vikas Belamkar, Nick Garst, Jackie Rudd, Amir Ibrahim, Anil Adhikari, P. Stephen Baenziger.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Easterly, A. C., N. Garst, V. Belamkar, A. M. H. Ibrahim, J. C. Rudd, J.-B. Sarazin, and P. S. Baenziger. 2020. Evaluation of Hybrid Wheat (Triticum aestivum L.) Yield in Nebraska. Crop Science 60:1-13 . https://doi.org/10.1002/csc2.20019.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Easterly, A. C., W. Stroup, N. Garst, V. Belamkar, J.-B. Sarazin, T. Moittie, J.-B. Sarazin, A. M. H. Ibrahim, J. C. Rudd, E. Souza, and P. S. Baenziger. 2019. Determining the efficacy of a hybridizing agent in wheat (Triticum aestivum L) .Scientific Reports 9:1-11.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., A. M. H. Ibrahim, J. C. Rudd, P. S. Baenziger, and J.-B. Sarazin. 2020. Estimation of Heterosis and Combining Abilities of U.S. Winter Wheat Germplasm for Hybrid Development in Texas. Crop Science 60:788-803
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., A.M.H. Ibrahim, J.C. Rudd, P.S. Baenziger, A. Easterly, N. Garst, V. Belamkar, J.-B. Sarazin. 2020. Supplementing selection decisions in a hybrid wheat breeding program by using F2 yield as a proxy of F1 performance. Euphytica 216: 130. [https://doi.org/10.1007/s10681-020-02664-0]


Progress 12/15/18 to 12/14/19

Outputs
Target Audience:The target audience will be small grains producers and their value chain from seed dealers to grain buyers, millers/maltsters/livestock producers, bakers and brewers, and consumers. While consumers are sometimes overlooked, they are the main determinant in our freedom to access new technologies, hence are critically important in understanding the value and safety of the research that is undertaken, especially hybrid research. Our scientific target audience will be plant and animal breeders, geneticists, and genomicists, crop physiologists and production specialists, plant pathologists, entomologists, cereal chemists and applied statisticians. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two graduate student successfully completed their field research for the M.S. and Ph.D. degrees. In addition, other students learned about hybrid wheat by helping with the extensive note taking, seed preparation, planting and harvest. How have the results been disseminated to communities of interest?In preparation for the launch of hybrid wheat, talks were given to the Nebraska Crop Improvement Association (80 seed dealers in attendance) and at three seed days in western Nebraska. In addition, Vikas Belamkar presented a talk on behalf of the project at the Plant and Animal Genome meeting in 2019 and two presentations were made at the annual meeting of the Crop Science Society of America. What do you plan to do during the next reporting period to accomplish the goals?We will continue our anther extrusion scoring, our female receptivity scoring, and our introgressoin of Rf genes into modern winter wheat lines. We will harvest our hybrid yield trials, spray our 2020 hybrid crossing block, and plant our 2021 hybird yield trial. We have added two new students to the project to replace the two that will be graduating and their research will be on hybrid wheat.

Impacts
What was accomplished under these goals? Objective 1. We continue to screen the Nebraska and Texas wheat breeding programs for anther extrusion (a male trait). 2019 was an excellent year to study this trait with generally cool and moist weather during flowering. In 2019, we evaluated for the third year, 299 lines the Hard Winter Wheat Association Mapping Panel (HWWAMP) developed as a resource for the Great Plains by the previous TCAP grant. The HWWAMP is being used in genome wide association studies to map QTLs for anther extrusion as these lines are already genotyped. As part of our chemical hybridizing agent (CHA) crossing block, we have noticed that the highest yielding crossing blocks are those where the delay between the male and female lines is good (females gape a few days before the males reach maximum pollen shed) and the male is an excellent pollinator as visually determined by anther extrusion. The best indicators of female receptivity appeared to be gape angle and 100% gape date (when all the spikes are gaping). Both female traits can be visually scored quickly and accurately. Other traits that were scored were duration of gaping, stigma exsertion, and gape closure. The female traits were highly correlated, so one or at most two could be used to select excellent female lines. Objective 2: We continue to use Croisor® 100 to make hybrids. We continue analyzing the data, removing the spatial variation, comparing reciprocal crosses, and estimating heritability and heterosis from our 25 x 26 crossing block with the emphasis on determining the genetics of heterosis. We successfully used the balanced missing design pioneered by our German cooperators for the 2017, 2018 and repeated it in 2019 crossing blocks. In this crossing block, we had 50 males and 100 females (total of 150 lines with 25 males and 50 females selected by both UNL and TAMU) where each male was crossed to 14 females. To ensure that environmental hazards did not destroy the crossing block, we grew two crossing blocks (1 in NE and 1 in TX). Hybrid seed yields were much higher in 2019 than in 2018 due to the better weather conditions. We evaluated for the second year the hybrid yield trials (total of six locations (3 in NE and 3 in TX). As in the past, heterosis was present particularly in stressed environments showing climate resiliency of hybrid wheat. On the basis of the results of yield results, we developed specific hybrids trials with 3 replications to validate our augmented design research (needed due to the large number of entries in the hybrid yield trials, often > 800 plots). Finally, we completed the third year of a small experiment to study CHA rates and different adjuvants to reduce phytoxicity and the amount of chemical needed to sterilize wheat plants. In 2017, the trial was successful, but we were able to obtain more of the European surfactants/adjuvants for the 2018 and 2019 trials. The surfactants allow lower rates of the CHA to be used, hence less phytotoxicity. In the 2019 trial, we sprayed slightly early due to persistent rains. NI13706 was hard to sterilize all three years, while NE09517 seemed to be easier to sterilize. The window of CHA application is narrow and later spray applications need higher CHA rates to be effective. As part of our international collaboration, we grew a small hybrid trial developed in Germany. As expected the German hybrids and parent lines were late developing compared to Nebraska lines. This year, the later German hybrids were severely affected by late heat stress as seen in dramatically lower grain yields. Objective 3: All of the parental line have been genotyped, and the genomic and phenotypic analyses were completed to be point where we can predict using our hybrid yeild data from 2018 and 2019 which hybrids should be made to obtain the highest levels of heterosis. We planted a crossing block in NE and TX based on the predicted hybrids we want to test in 2020-21. Objective 4: The evaluation of a biparental mapping population for restorer (Rf) genes was completed. While some previously known Rf genes were found, additional novel Rf were mapped suggesting that this population based on one of the best restorer lines in Australia was a rich source of pyramided restorer genes. Work continues to develop through crossing and evaluation, modern winter and spring wheat restorer lines and male sterile lines using the Triticum timopheevi cytoplasm.

Publications

  • Type: Journal Articles Status: Under Review Year Published: 2020 Citation: Easterly, A.C., N. Garst, V. Belamkar, A.M.H. Ibrahim3, J. C. Rudd, J.-B. Sarazin, and P. S. Baenziger. Evaluation of Hybrid Wheat (Triticum aestivum L.) Yield in Nebraska. Crop Sci: under revision. Determining the Efficacy of a Hybridizing Agent in Wheat (Triticum aestivum L.) Crop Science: under revision
  • Type: Journal Articles Status: Under Review Year Published: 2020 Citation: Adhikari, A., A. M.H Ibrahim, J. C. Rudd, P. S. Baenziger, and J.-B.t Sarazin. Estimation of Heterosis and Combining Abilities of U.S. Winter Wheat Germplasm in Texas. Crop Science: under revision.
  • Type: Journal Articles Status: Under Review Year Published: 2020 Citation: Easterly, A.C., N. Garst, V. Belamkar, J.-B. Sarazin, T. Moittié, A. M.H. Ibrahim, J. C. Rudd, W. W. Stroup, E. Souza6, and P. S. Baenziger. Determining the Efficacy of a Hybridizing Agent in Wheat (Triticum aestivum L.). Scientific Reports: under revision.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Gupta, Pushpendra Kumar, Harindra Singh Balyan, Vijay Gahlaut, Gautam Saripalli, Bijendra Pal, Bhoja Raj Basnet, and Arun Kumar Joshi. 2019. ⿿Hybrid Wheat: Past, Present and Future.⿝ Theoretical and Applied Genetics 132 (9): 2463⿿83. https://doi.org/10.1007/s00122-019-03397-y.


Progress 12/15/17 to 12/14/18

Outputs
Target Audience:Our target audience includes growers, seed dealers, wheat researchers in the public and private sector, and consumers. We gave talks/presentations at grower field days and seed days, at the Crop Improvment Association meetings, at the Crop Science Society of America and at the Plant and Animal Genome meeting, and held an open workshop/meeting with our Scientific Advisory Board (which incldes breeding companies, equipment manufacturers, and millers and bakers) using ZOOM so that our international collaborators could particpate. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Our students are attending and presenting at national and internatiional meetings. We hosted a Borlaug Fellow to learn about hybrid wheat production. Our Scientific Adviosory Board allowed our student and faculty to meet and understand the capabilities and needs of commercial seed development which allowed them insights on diverse career pathways (i.e. more than academia). How have the results been disseminated to communities of interest?In preparation for the launch of hybrid wheat, talks were given to the Nebraska Crop Improvement Association (80 seed dealers in attendance) in January 2018 and at three seed days in western Nebraska ( approximately 300 growers in attendance) in August, 2018. Our students made poster presentations at the Crop Science Scoeity of America annual meeting in 2017 and will do so in 2018. Vikas Belamkar presented a talk on behalf of the project at the Plant and Animal Genome meeting in 2018 in a workshop titled "Hybridization, Heterosis and Balancing Selection." We have now deposited the variant and SNP calls along with the genotyping-by-sequencing data - FASTQ files at the IWYP Wheat Data Repository at International Maize and Wheat Improvement Center (CIMMYT). We will also deposit the new variant and SNP calls made in 2018 and all the phenotypic data associated with this project. Currently, the data sets are fully restricted and will be made public in the future. What do you plan to do during the next reporting period to accomplish the goals?Obj. 1: In 2018-2019, we will continue to screen our elite Nebraska germplasm (300 to 400 lines in Nebraska) for anther extrusion and the HWWAMP for the third and final season. We will also screen at least 270 new lines (preliminary yield trial) and the regional performance nurseries (90 lines) for anther extrusion. In addition, we will continue to study the needed female characteristics (female gape and duration, and stigma receptivity) for increased hybrid seed set. In Texas, the same 80 lines, representing the 2016 UVT and TXE will be grown again in fall 2017 and 2018 and screened for genotype-by-environment interaction of anther extrusion and female stigma exertion and gape in 2019 at College Station and McGregor. Furthermore, 320 lines representing the advanced pipeline of Texas breeding program, including the 2018 UVT, TXE, STA 1 - 2, and STP 1- 4, will be screened for anther extrusion and female stigma exertion and gape at College Station, TX. Obj. 2. We will replant our hybrid crossing block to make additional hybrid seed for testing. We will repeat and update our experiment to study CHA rates and different adjuvants to reduce phytoxicity and the amount of chemical needed to sterilize wheat plants. We will plant hybrid yield trials at six locations (three in Nebraska and three in Texas). These trials use a balanced missing design hybrid which is critical to use the algorithms developed by our German cooperators to identify heterotic pools. We will finish our analyses and publish our complete 25 x 25 plus one diallel. By having reciprocal hybrids, we will learn if some lines are better as females or males based upon hybrid yield (as opposed to making the decision on floral characteristics). We can also use the diallel hybrid data to selectively drop some of the hybrids and predict their performance from our GBS data and the balanced missing algorithms to increase our understanding of how to better predict hybrids. The parental trial that will be grown at four locations in 2019 will allow for robust estimation of the parent-hybrid heterosis estimates. This is especially critical given the fact that we observed significantly high GXE in 2018. Hence, by growing the parental lines at the same locations as the hybrids, we will be observing and estimating heterosis at the same locations. This will also assist any additional genomics work because the investigation at the genetic level will be correlated with the heterosis observed in the same environment. Obj. 3: Genomic predictions and development of heterotic groups and patterns has to wait until we have the second year of the hybrid field trials analyzed and the spatial variation removed or accounted for so that we have the most accurate estimates of the hybrid values. We expect to do preliminary analyses to develop our analysis pipeline before we have the second year of data. One aspect of the balanced missing data analyses is that the number of tested hybrids needs to be large. We will begin to study the statistical and prediction power of hybrid trials after harvest in 2019. Our belief is that it may be possible to do replicated hybrid trials involving fewer hybrids that will increase our heritabilities and prediction accuracies. This is explicit in our current analysis with the diallel dataset. Our prediction accuracies were significantly higher in 2017 than 2016 and were highest when both 2016 and 2017 datasets were combined. We think we will need additional screening (hence the same crosses are being made in 2018-2019 - which will provide three years of hybrid yield trial dataset) to increase heritability since the size of these balanced missing experiments to identify heterotic pools are large. We will continue working on the genomic predictions and testing different cross-validation schemes using the diallel dataset. Specifically, we will run cross-validations by explicitly accounting for the genetic distance between the training and test sets while making the predictions. Obj. 4. Refine and produce high quality genetic linkage map from the mapping population by verifying the genetic as well as physical map position of these markers. Comprehensive analysis of marker-trait association using different traits, such as % sterility and total seed set measured in 10 bagged spikes per cross and RIL, which are being precisely evaluated in the current growing season at El Batan, Mexico. Test cross progenies will be further evaluated in two field locations of Mexico in upcoming growing season (November to May). This will enable us to further characterize the Rf genes and identify their best combinations for stable expression of fertility restoration across different environments. Once the preliminary mapping is complete, for the significant loci, KASP markers will be developed and tested in RILs and other R-Lines available at CIMMYT.

Impacts
What was accomplished under these goals? Obj. 1. We continued screening our advanced populations for anther extrusion. Due to extreme termpleratures (>39 C at flowering) in eastern Nebraska, the results were most likely not very useful as many previously good anther extruding lines were not particularly good this year. For female characteristics, the CHA sprayed female lines in the crossing block were scored for gape date, duration of gaping, stigma exsertion, and gape closure to begin to understand the female side of hybrid wheat production. The gape day was recorded when 50% of the plot was gaping, and when 100% of the plot was gaping. Gape angle and stigma exsertion were both scored on these days. 50% gape day ranged from 143 Julian days to 152 Julian days in the hybrid crossing block. In Texas with more normal weather, 80 lines were evaluated representing the Texas Uniform variety Trial (UVT) and Texas Elite (TXE) flor male (anther extrusion and anther score) and female (gape and stigma exertion) floral characteristics in the spring of 2017 and 2018. To obtain reliable readings of the female traits, we applied Croisor® 100 chemical hybridizing agent at Zadocks 34 stage in 2018. We have also taken notes on days to anthesis and plant height on all entries. All gender and non-gender traits were significantly different among lines in both UVT and TXE trials. Repeatability of the non-gender traits (days to anthesis and plant height) were high (0.90 - 0.98) in both 2017 and 2018. Repeatability of anther extrusion and anther score were moderate to high (0.62 - 0.70) whereas repeatability for the female traits were generally poor (0.05 - 0.37). Obj. 2. We successfully used the balanced missing design pioneered by our German cooperators for the 2017 and repeated it in 2018 crossing blocks. In this crossing block, we had 50 males and 100 females (total of 150 lines with 25 males and 50 females selected by both UNL and TAMU) where each male was crossed to 14 females. To ensure that environmental hazards did not destroy the crossing block, we split our crossing blocks between NE and TX. The NE (25 males and 100 females) and one of the TX (the remaining 25 males and the same 100 females) crossing blocks worked very well with a range of seed produced from 65g to 2070 g with an average of 657g in Lincoln and 24g to 1182g with an average 326g in Texas in 2017. The harshness of the environments in 2018 reversed the hybrid seed production with Texas producing hybrid seed under irrigation from 418 g/plot to 2697 g/plot with an average of 1595 g/plot and Nebraska with the extreme heat at flowering producing hybrid seed ranging from 22.6g to 1781g with an average of 240g. Obj. 3.All of the 150 parents have now been genotyped.We did not observe any strong population structure and as observed within the panel of 150 parental lines, there were mainly three clusters - one containing just Nebraska lines, and the other containing just Texas lines, and a third one containing both Nebraska and Texas lines.All six-hybrid yield trials (augmented designs using incomplete block designs with iblocks of 50 [40 hybrids and 10 commercial checks where 3 checks were from TX, 3 checks were from NE and 4 checks were completely unrelated to the TX or NE parent gene pools]) were harvested in 2018 (representing over 4000 harvested plots). We have begun analyzing these data and building our analysis pipeline. Also, we have started the genomic analyses of the ~650 hybrids that were made using a full diallel design comprising 26 parents in 2015 and 2016 and the hybrid yield trials conducted in 2016 and 2017 at six locations (three in NE and three in TX). Although this work is not part of this grant, the knowledge and understanding gained will be relevant to the hybrid wheat efforts. Also, the analysis workflow built with the diallel experiments can easily be extrapolated to the larger crossing block used in the current grant. Obj. 4. For genetic mapping of fertility restoration, an Australian restorer source with T. timopheevii cytoplasm was crossed with a CIMMYT line (T. aestivum cytoplasm) and the progenies were advanced to the F4 generation to develop a recombinant inbred population. Leaf tissue was harvested from the RIL population in the greenhouse and genotyped with 19000 SNP chip from TraitGenetics. The test cross visual observation, total seeds per RIL and total sterile spikelets per spike were used to conduct a marker trait association using single marker regression method in QTL ICI mapping software. Significant marker trait associations (LOD>4) were observed in chromosomes 1A, 1B, 1D, 6B and 7B. These loci might represent some of the previously reported Rf genes in A and B genome, and potentially a novel one in D genome.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Belamkar, V., M. J. Guttieri, W. Hussain, D. Jarqu�n, I. S.El-basyoni, J. Poland, A. J Lorenz, P. S. Baenziger. 2018. Genomic Selection in Preliminary Yield Trials in a Winter Wheat Breeding Program. G3: Genes, Genomes, Genetics 8:2735-2747. https://doi.org/10.1534/g3.118.200415


Progress 12/15/16 to 12/14/17

Outputs
Target Audience:The target audience includes commercial seed producers, purchasers of advanced and improved seed, millers and bakers, biotechnologists, plant breeders, and those that consume wheat. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Vikas Belamkar (partially funded from this grant) attended a R-workshop on "Advanced R Programming for Statgen package development" at the Summer Institute in Statistical Genetics 2017, University of Washington, Seattle, WA July 12-14, 2017 and will be transferring this knowledge to our group. How have the results been disseminated to communities of interest?In preparation for the launch of hybrid wheat, talks were given to the Nebraska Crop Improvement Association (80 seed dealers in attendance) in January 2017 and at three seed days in western Nebraska ( approximately 300 growers in attendance) in August, 2017. What do you plan to do during the next reporting period to accomplish the goals?Obj.1: In 2017-2018, we will continue to screen our elite Nebraska germplasm (300 to 400 lines in Nebraska) for anther extrusion and the HWWAMP. In addition, we will begin to study the needed female characteristics (female gape and duration, and stigma receptivity) for increased hybrid seed set. In Texas, the same 80 lines, representing the 2016 UVT and TXE will be grown again in fall 2017 and screened for genotype-by-environment interaction of anther extrusion and female stigma exertion and gape in 2018 at College Station and McGregor. Furthermore, 320 lines representing the advanced pipeline of Texas breeding program, including the 2018 UVT, TXE, STA 1 - 2, and STP 1- 4, will be screened for anther extrusion and female stigma exertion and gape at College Station, TX. Obj.2: We will replant our hybrid crossing block to make additional hybrid seed for testing. We will repeat our experiment to study CHA rates and different adjuvants to reduce phytoxicity and the amount of chemical needed to sterilize wheat plants. We will plant hybrid yield trials at six locations (three in Nebraska and three in Texas). These trials use a balanced missing design hybrid which is critical to use the algorithms developed by our German cooperators to identify heterotic pools. We will continue to analyze our complete 25 x 25 plus one diallel. By having reciprocal hybrids, we will learn if some lines are better as females or males based upon hybrid yield (as opposed to making the decision on floral characteristics). We can also use the diallel hybrid data to selectively drop some of the hybrids and predict their performance from our GBS data and the balanced missing algorithms to increase our understanding of how to better predict hybrids. Obj.3: We were successfully able to genotype all 26 lines in our original hybrid diallel and 143 lines of the 150 in our balanced missing crossing block. The seven lines that were not successfully genotyped will be resubmitted for genotyping, as will all new lines added to the crossing block. Genomic predictions and development of heterotic groups and patterns has to wait until we have the hybrid field trials analyzed and the spatial variation removed or accounted for so that we have the most accurate estimates of the hybrid values. We expect those analyses to be done on the diallel hybrid set by December and we will begin working on the heterotic group identification thereafter. Also, the potential number of hybrids is so much larger using the balanced missing design than with the complete diallel design, the full effort on heterotic groups will have to wait until we can analyze next year's hybrid yield trial. Obj.4: CIMMYT and Texas: To further validate the mapping results and develop KASP markers for Rf genes, a F4:5 recombinant inbred line (RIL) populations is being developed at El Batan. In 2017-18 growing season, each F5 line will be crossed with a CMS line to produce enough F1 seed for field evaluations in 2-3 environments. Once the diagnostic molecular markers are developed, individual Rf genes and combinations will be further evaluated for their ability to restore fertility in order to identify the best set of Rf genes necessary in CMS based hybrid wheat system. Similarly, newly developed CIMMYT restorer lines will also be haplotyped in order to confirm the presence of Rf genes. Nebraska: We will continue to backcross our elite lines into T. timopheevi cytoplasm to create new A-lines and develop sufficient seed for CMS based hybrids. Our convectional breeding program to create new R-lines (R-line x B-line crosses followed by selection for fertility) will continue. As molecular markers are identified, these R-lines will be screened to determine which restorer genes (Rf) they may have. We will also begin making crosses to ensure they have sufficient restorer genes to restore our A-lines in hybrid combinations.

Impacts
What was accomplished under these goals? Obj. 1: We have continued to screen our advanced breeding materials for anther extrusion. Previously, in Nebraska we screened the preliminary, advanced, and elite yield trials, as well as the regional performance nursery for a total of 288 lines in the field for the second year. A select group of lines (29 lines) was also screened for anther extrusion in the greenhouse. The anther extrusion ranged from 2 to 7 (on a scale where one indicated that few anthers, or only the tip of most anthers are visible outside of the glumes at anthesis, and nine indicating that many anthers were fully exposed outside of the florets at anthesis) in the field, but there was considerable genotype by environment (GxE) interactions. Over fifty percent of the lines had scores of 5 or above (considered to be adequate to be a male line in hybrid production). While some lines (e.g. Freeman, scored as 7) consistently had high values for anther extrusion and other lines consistently had poor anther extrusion (e.g. Camelot scored as 2), many lines exhibited higher environmental variability. The broad sense heritability for anther extrusion was relatively high (ranging from 0.62 to 0.85 depending upon the nursery). In 2017 we screened an additional 120 lines and 299 lines the Hard Winter Wheat Association Mapping Panel (HWWAMP) developed as a resource for the Great Plains by the previous TCAP grant. The HWWAMP will be used in genome wide association studies to map QTLs for anther extrusion. In Texas, we have screened TAMU wheat breeding nurseries (SOBS, AOBS, STP1-STP4, and AP1-AP10) and lines from UNL (NIN, TRP, IRDR, RPN; approximately 600 lines) for floral characteristics in spring 2014, and 100 promising lines were selected and planted at College Station during fall 2014. A set of promising 180 TAM germplasm lines, selected for floral characteristics, was planted in the field at College Station and McGregor in fall 2016 (representing STP 1 - 4, TXE, UVT) to look at genotype-by-environment interaction for anther extrusion and female stigma exertion and gape. Obj. 2: We used Croisor® 100 make hybrids from a 25 female x 25 male complete diallel. For efficient field work, an additional female line was added making the crossing block 25 males by 26 females (hereafter referred to as a 25 x 25 diallel plus one). Visual ratings for CHA induced floral gaping and phytotoxicity due to CHA application was recorded. Few heads in every female plot were bagged to estimate the efficacy of the CHA. Ideally, the bagged heads were completely sterile indicating that the CHA worked, and the seed set on the unbagged heads was good indicating that there is good cross-pollination and few phytotoxic effects. The female plots were harvested to measure grain yield. In 2015, 80% of bagged heads in the females had 10 seeds or fewer, whereas 93% had 5 seeds or fewer in 2016, so adequate sterility was achieved for our hybrid seed production. We completed our first year of hybrid evaluation trials in 2016 (three locations in NE and one in TX) and our second year (three locations in NE and two in TX) in 2017. An augmented incomplete block design was used as hybrid seed is precious and the trials are very large (complete replications would be impossible). Due to limited seed, not every hybrid was tested at every location. However, at least 550 hybrids were tested at the five locations in 2017. Complete sets of the diallel crosses (650 hybrids) were harvested at two locations in Nebraska, in Lincoln and at North Platte. We are now working on analyzing the data, removing the spatial variation, comparing reciprocal crosses, and estimating heritability and heterosis. We successfully used the balanced missing design pioneered by our German cooperators for the 2017 crossing block. In this crossing block, we had 50 males and 100 females (total of 150 lines with 25 males and 50 females selected by both UNL and TAMU) where each male was crossed to 14 females. To ensure that environmental hazards did not destroy the crossing block, we grew three crossing blocks (1 in NE and 2 in TX). The NE (25 males and 100 females) and one of the TX (the remaining 25 males and the same 100 females) crossing blocks worked very well with a range of seed produced from 65g to 2070g with an average of 657g in Lincoln and 24g to 1182g with an average 326g in Texas. The seed from both crossing blocks has been sent to Lincoln for designing the hybrid yield trials for six locations (three in Nebraska and three in Texas). Obj. 3: DNA isolation, genotyping-by-sequencing, SNP calls: The 150 lines in the crossing block were genotyping-by-sequencing (GBS) at the Wheat Genetics and Germplasm Improvement Laboratory (WGGIL) at Kansas State University. Subsetting the SNP calls for the 150 parental lines and filtering SNPs and lines with appropriate quality control (excluded SNPs and lines with >20% missing information and SNPs with minor allele frequency (MAF) <0.05) resulted in 143 lines and 39,960 high-quality SNPs. This dataset filtered with high-stringency was then used to investigation population structure of the parental lines. Seven parental lines with more than 20% missing information will be re-genotyped using GBS in 2017-2018. The 280,285 SNPs obtained in the SNP calling were filtered to retain high-quality SNPs and the missing sites were imputed using Beagle v4.1. The parental lines were subdivided and SNPs with MAF>0.05 were retained. This resulted in 114,436 SNPs across 150 lines. Subsequently, we built 11,175 hybrids in silico using CreateHybridGenotypesPlugin in TASSEL. The hybrid dataset was filtered for retaining SNPs with MAF>0.05 and maximum missing sites less than 20%, which resulted in 56,719 high-quality SNPs across the hybrids. This indicates, we will very likely have more than 50K SNPs across the 11,175 hybrids to run the prediction in 2018-2019. For investigating the population, we added an additional filter and excluded hybrids with >20% missing sites. This resulted in 56,470 high-quality SNPs across 10,731 hybrids for the population structure analysis in the hybrids. The population structure was investigated using principal component analysis (PCA) and a phylogeny based on Neighbor joining (NJ) algorithm. We found that the parental lines are quite diverse based on PCA and there were two outgroups, one comprising five lines from the Nebraska (NE) breeding program and the other containing five lines from the Texas (TX) program. The remaining lines were weakly structured into:1) mainly lines from NE, 2) mainly lines from TX, and 3) lines from both from NE and TX. Structure among the hybrids is similar to the parents but with a significantly higher overlap/increased kinship. Obj. 4: A BC1F1 mapping population of spring wheat genotypes (n = 280) was developed by crossing a restorer source (T. timopheevii cytoplasm) with an advanced line (T. aestivum cytoplasm) at El Batan, CIMMYT. In 2016-17 growing cycle, the BC1F1 population was phenotyped for fertility restoration by counting the number of fertile lateral florets and total number of seeds per spike present in a set of three spikes per genotype. The spikes were covered with glassine bags before flowering to prevent cross fertilization and contamination. The individual BC1F1 plants have also been genotyped using a 20K SNP chip. The genotypic data will be filtered for monomorphic markers and missing data and will be used to map regions corresponding to fertility restoration. Software package ICIMapping (Integrated Breeding Platform, https://www.integratedbreeding.net/) will be initially used to map genomic regions corresponding to fertility restoration using simple interval mapping and inclusive composite interval mapping (ICIM) algorithm. We expect to have preliminary mapping results by the end of 2017.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hybrid Wheat for the Great Plains: Improving Yields and Water Efficiency? Poster presented by Amanda Easterly at the Daugherty Water for Food Global Institute at the University of Nebraska 2017 Annual Conference in April 2017. Authors: Amanda Easterly, Vikas Belamkar, Nick Garst, Jackie Rudd, Amir Ibrahim, Anil Adhikari, P. Stephen Baenziger.
  • Type: Journal Articles Status: Under Review Year Published: 2017 Citation: Evaluation and implementation of genomic selection in preliminary yield trials in the University of Nebraska winter wheat breeding program. Vikas Belamkar, Mary J. Guttieri, Waseem Hussain, Diego Jarqu�n, Ibrahim El-basyoni, Jesse Poland, Aaron J. Lorenz, P. Stephen Baenziger. Manuscript submitted on August 01, 2017 to Theoretical and Applied Genetics. Status: Pending major revisions.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Screening Great Plains Winter Wheat (Triticum aestivum L.) Germplasm for Anther Extrusion and Evaluating the Effect of Anther Extrusion on Hybrid Seed Production Yields Nicholas Garst Masters Defense seminar and thesis
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Diversity and Performance of Wheat Hybrids in the Great Plains. Poster and 5 minute oral presentation by Amanda Easterly at the 2016 ASA/CSSA/SSSA International Meeting in Phoenix, AZ. Authors: Amanda Easterly, University of Nebraska - Lincoln; Nicholas Garst, University of Nebraska - Lincoln; Vikas Belamkar, University of Nebraska - Lincoln; Jackie C. Rudd, Texas A&M AgriLife Research; Amir M.H. Ibrahim, Texas A&M University; P. Stephen Baenziger, University of Nebraska - Lincoln
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Modeling Male Sterility Induced by Chemical Hybridization of Wheat (Triticum aestivum L.) Poster presented by Amanda Easterly at the Conference in Applied Statistics, Manhattan, KS, April 2017. Authors: Amanda Easterly, Nicholas Garst, Vikas Belamkar and P. Stephen Baenziger  University Nebraska-Lincoln