PLANT BREEDING PARTNERSHIPS: CONTINUING TO DEVELOP AND VALIDATE THE TOOLS FOR HYBRID WHEAT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1022107
• Grant No.: 2020-67013-30872
• Cumulative Award Amt.: $650,000.00
• Proposal No.: 2019-05456
• Project Start Date: Jun 1, 2020
• Project End Date: May 31, 2023
• Grant Year: 2020
• Program Code: [A1141]- Plant Health and Production and Plant Products: Plant Breeding for Agricultural Production

Recipient Organization
UNIVERSITY OF NEBRASKA
(N/A)
LINCOLN,NE 68583

Performing Department
Agronomy and Horticulture

Non Technical Summary
The long-term goal of this project is to develop the necessary knowledge base, germplasm, and heterotic pools or patterns 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 this goal. The project objectives are to: 1) validate heterosis from previously made and predicted wheat hybrids in replicated trials; 2) continue male and female (main emphasis) parent line evaluation for characteristics needed to develop experimental and commercial wheat hybrids in a cost-efficient manner; 3) develop heterotic groups or patterns and test multiple mating designs for wheat hybrids; and 4) continue cytoplasmic male sterility line development and identify and validate restorer genes for wheat hybrids. The project team has made great strides toward developing 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 a U.S. hybrid wheat industry and is thus relevant to the AFRI program, specifically Plant Breeding for Agricultural Production (A1141). It is also relevant to Global Engagement by partnering with CIMMYT, a member of the Consultative Group on International Agricultural Research system whose mission is to reduce poverty and hunger.

Animal Health Component

50%

Research Effort Categories

Basic

25%

Applied

50%

Developmental

25%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
202	1540	1081	75%
201	1540	1080	25%

Knowledge Area
202 - Plant Genetic Resources; 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1540 - Hard red winter wheat;

Field Of Science
1081 - Breeding; 1080 - Genetics;

Keywords

genetics

great plains

heterosis

hybrid

wheat

yield

Goals / Objectives
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 or patterns to support the development of hybrid wheat. Toward this end, the specific objectives of this project are to:1. Validate heterosis from previously made and predicted wheat hybrids in replicated trials. 2. Continue male and female (main emphasis) parent line evaluation for characteristics needed to develop experimental and commercial wheat hybrids in a cost-efficient manner.3. Develop heterotic groups or patterns and test multiple mating designs for wheat hybrids. 4. Continue cytoplasmic male sterility (CMS) line development and identify and validate restorer genes for wheat hybrids.

Project Methods
Objective 1: Validate heterosis from previously made and predicted wheat hybrids in replicated trials (Leads: UNL and TAMU). The first step will be to use seed from the existing crossing blocks to select approximately 60 high yielding hybrids for Nebraska and Texas. In these validation trials, 50 hybrids will be selected based on their performance in Nebraska or Texas (as hybrid vigor is environmentally specific). We will also select the 10 best hybrids that have done well in both Texas and Nebraska and 10 check cultivars (previously used in our hybrid yield trials) for a total of 70 entries per trial. Each hybrid yield validation trial will be grown in an alpha lattice with three replications in three locations in three distinct ecological zones in Nebraska (Alliance, North Platte, and Lincoln) and Texas (Greenville, McGregor, and Bushland). The second part of this objective is to validate our genomic estimated breeding values (GEBVs) of the 10,475 predicted but untested hybrids (e.g., 150 parental lines = 11,175 possible hybrids - 700 tested hybrids in the field; see section 1.2 for details). We will use the ~700 tested hybrids and their spatially corrected yield values as a training dataset in the genomic prediction model and predict the yield of the remaining 10,475 hybrids (Zhao et al., 2015 and Belamkar et al., 2018 for methods). Subsequently, using the GEBVs on untested hybrids, we will select three groups of hybrids with a total of ~160 entries that includes 10 checks to connect with our previous trials. The three groups will be: 1) 90 hybrids predicted to be the highest-yielding hybrids (which should likely have high heterosis values); 2) 30 hybrids predicted to be low-yielding hybrids (which should likely have low heterosis values); and 3) 30 random sets of hybrids. We are testing these three sets of hybrids to test the accuracy of predictions. The validation hybrids will need to be made; hence, we will need to put them into our crossing block in 2019-2020 to create new hybrids for testing in 2020-2021 and possibly 2021-2022.Objective 2: Continue male and female (main emphasis) parent line evaluation for characteristics needed to develop experimental and commercial wheat hybrids in a cost-efficient manner (Leads: UNL and TAMU). We did not find the presence of major effect locus for anther extrusion. Hence, the trait architecture seems to be complex or unknown. We propose to phenotype the Freeman X Camelot (best X worst extruder) doubled haploid population comprising 175 lines for anther extrusion and pollination duration for an additional two years (2019-2020 and 2020-2021) and perform QTL mapping using GBS data to investigate the trait architecture and identify genomic regions important for this trait (for methods see Hussain et al., 2017). Additionally, at UNL and TAMU, we will continue screening advanced nurseries in the pureline program each year for anther extrusion (as part of the breeding program efforts when possible). We will then be able to predict the male characteristics of new breeding lines without phenotyping them in the field for these traits (if we are able to get reasonably high prediction accuracy). The second part of this objective will involve screening for female characteristics, and this aspect will be emphasized in this proposal as part of the student research. The key female traits include gape date, glume angle, stigma size exsertion, and featheriness duration. Preliminary GWAS indicated the presence of major effect loci for some of these traits, as opposed to male traits where such associations could not be identified. Hence, in the proposed project, we will phenotype all the new female lines that will be part of the new crossing blocks beginning in 2019-2020. This effort will increase our population size on which the female traits are measured and allow for a robust GWAS to identify genomic regions and underlying genes associated with female characteristics. Using markers and predicting female lines is much less labor intensive than phenotyping new female lines.Objective 3: Develop heterotic groups or patterns and test multiple mating designs for wheat hybrids (Leads: UNL, TAMU, IPK, and Iowa State University [ISU]). The selection of parents to develop new hybrids will need to take into account male and female characteristics and also the GCA and SCA values. The first part of this objective is to investigate this complete matrix (representing the largest wheat growing region in the United States) for heterotic groups and patterns (using the methods built by our IPK collaborator and described in Zhao et al., 2015b). If successful, the second part of the objective would be to design the crossing block to begin investigating and developing these heterotic groups and patterns in 2021 and 2022. Based on our data so far and the analytical pipelines UNL and IPK have built, we will analyze the 2018 and 2019 field hybrid yield trials for the indication of heterotic patterns in 2019-2020, which means the first crossing block developed from these analyses will occur in 2020-2021 and the yield trials will be grown in 2021-2022. The crossing blocks will use the balanced missing design of Zhao et al. (2015b) or, if we are able to identify heterotic patterns, the designs of Guo et al. (2018).Objective 4: Continue CMS line development and identify and validate restorer genes for wheat hybrids (Leads: CIMMYT, UNL, and TAMU). In our previous research (described in section 1.2), we have focused on mapping restorer genes in T. timopheevi cytoplasm, creating a series of CMS tester lines, their maintainer lines, and a series of elite restorer lines (R-lines). Fine mapping of each major QTL/gene. The previously identified QTL regions will be saturated using high-density markers and large-size single gene mapping backcross or F2 populations. Subsequently, more diagnostic markers will be developed and validated in a diverse set of germplasm. Candidate gene sequencing. Our previous work involving QTL mapping and RFL gene family analyses has identified RFL genes in the wheat genome likely contributing to restoration ability. We will perform targeted re-sequencing (also referred to as amplicon sequencing) of these candidate RFL genes across ~96 to 192 samples and identify SNPs and indels (likely functional alleles) within these candidate genes. The samples will include selected RILs), parents and CMS-tester lines, QTL/gene specific backcross or F2 population, CARGILL R-lines, R lines developed in the ongoing project, and selected non-R lines. Method for targeted/amplicon sequencing. We will use Illumina's NextSeq Series Amplicon Sequencing Solution using the TruSeq Genotype Ne kit. Once Illumina prepares the custom oligos, they will ship the custom oligos and all reagents required for the library construction and sequencing to the University of Nebraska Medical Center (UNMC) Sequencing Core Facility led by Dr. James Eudy. The samples will be sequenced on Illumina's NextSeq machine (1 X 150 bp read lengths) to 100X depth.Comparing genetically identical CMS vs. CHA hybrids. Three crosses will be made to observe the effect of CMS/CHA on hybridity, seed set, and grain yield. The three crosses will be: 1) A-Line (CMS) x R-line; 2) R-line sprayed with CHA to become male sterile x B-line maintainer of the A-line in the first cross; and 3) B-line sprayed with CHA x R-line

Progress 06/01/20 to 05/31/23

Outputs
Target Audience:Our main stakeholders are small grain producers that can benefit from the improved grain yield and yield stability provide by hybrid wheat. Increased yield and stability has the potential to benefit the entire wheat value chain by providing end users such as milling and baking companies, livestock producers, and consumers by maintaining production while reducing input requirements and their requisite costs. We reach these stakeholders through annual field day presentations in Nebraska and Texas, meetings such as the Nebraska Crop Improvement Association Meeting or Wheat Quality Council, and we use Twitter and other media to share or research informally. Our scientific stakeholders include breeders and geneticists as well as researchers involved in plant stress resistance such as crop physiologists, pathologists, and entomologists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?2 Students from UNL presented posters at the 2022 National Association of Plant Breeders 1 Post doc from UNL presented a poster at the 2023 PAG meeting 1 M.S. student graduated in December 2022 with a thesis on female floral characteristics. 1 post doc at UNL working on QTL mapping for anther extrusion. Graduate students at UNL, TAMU and IPK are continuing analysis of the hybrid data we generated during this grant. How have the results been disseminated to communities of interest?We are disseminating our results through scientific publications (including 1 in 2023) and germplasm under the relevant MTAs. We shared research presentations to farmer and crop advisor stakeholders in Nebraska and to peer scientists at the 2023 PAG meeting and the 2023 McFadden Symposium. See details: Presentations: Ibrahim, A. and K. Frels. Designing a hybrid wheat program in the public sector. In: 2023 McFadden Wheat Symposium, Grapevine, TX; April 24-26, 2023. Frels, K. and A.C. Easterly. Opportunities and challenges with hybrid wheat in Nebraska. In: 2023 Nebraska Certified Crop Advisors Meeting, Kearney, NE; Feb 15-16, 2023. Frels, K., N. Miller, S. Sakhale, V. Belamkar, N. Garst, A.C. Easterly, PS. Baenziger, and A. Ibrahim. Evaluating heterosis and heterotic group potential in hard winter wheat. In: 2023 Plant and Animal Genome Conference, San Diego, CA; Jan 13-18, 2024 Ibrahim, A., K. Frels, A. Adhikari, P.S. Baenziger, B.R. Basnet, S. Dreisigacker, J.C. Rudd, B. Sade, J. Tadlock, B. Gerrish, N. Subramaniam, G. Opeña, S. Liu. Frels. Designing a hybrid wheat program in the public sector. In: 2023 Plant and Animal Genome Conference, San Diego, CA; Jan 13-18, 2024. Posters Sakhale, S.*, E. Karahan, V. Belamkar, N. Garst, P.S. Baenziger, and K. Frels. Exploration of the genetics of male fertility traits critical for hybrid seed production in wheat (Triticum aestivum L.) using a high-density linkage map in a double haploid population In: 2022 National Association of Plant Breeders Conference, Ames, IA. Aug 8-11, 2022. Jimenez, J.*, J. Yang, D. Jarquin, P.S. Baenziger, and K. Frels. Deciphering the genetic architecture of key female floral traits for hybrid wheat seed production. In: 2022 National Association of Plant Breeders Conference, Ames, IA. Aug 8-11, 2022. Sakhale, S.*, E. Karahan, V. Belamkar, N. Garst, P.S. Baenziger, and K. Frels. Exploration of the genetics of male fertility traits critical for hybrid seed production in wheat (Triticum aestivum L.) using a high-density linkage map in a double haploid population In: 2023 Plant and Animal Genome Conference, San Diego, CA; Jan 13-18, 2024 What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Obj.1. Heterosis between wide crosses were validated in multi-environmental field trials. A total of 44 F1 hybrids were produced by crossing 22 elite lines originating from the US with 2 elite lines originating from Germany (Figure 1). The US and German lines formed two clearly separated genetic clusters. Multi-environmental field trials were carried out in Lincoln/USA, Hohenheim/Germany (48°4'38.2''N8°55'27.6''E), Gatersleben/Germany (51°49'34.0''N11°16'20.6''E), and Schackstedt/Germany (51°42'47.5''N11°36'21.3''E). The experiments were conducted following an alpha lattice design with two replications. The plant material comprised the 44 hybrids, their 24 parents, and further 12 elite varieties. Grain yield was quantified as the grain weight harvested from each plot and expressed in kg per ha at a 14% moisture content. Heading date (HD) was assessed in days after the 1st of January when 75% of the spike per plot have emerged (Zadok scale 59; BBCH scale 59). Plant height (PH) was measured in cm from the ground to the erected ear after the flowering time (Zadok scale 71; BBCH 71). We subjected the raw data to a quality assessment. Outliers on each environment were identified following Anscombe and Tukey (1963). All outliers were removed from the dataset. The evaluation across the environments was carried out for the mega environments USA and Germany separately. For each trait, the best linear unbiased estimations (BLUEs) for genotypes across environments, replications and blocks were calculated a mixed model. The heritability varied between moderate and high, whereas the highest heritability was observed with 0.97 for the trait heading date in the German mega-environment and the lowest for grain yield in the USA (0.38). We observed a wide range of midparent heterosis estimatesunderlying the potential mutual options to broaden the germplasm pools by introgressing exotic lines. Obj. 2. Key female parent traits including gape date and gape angle were characterized on a diverse set of lines in 2021 and 2022. M.S. student Juan Jimenez (UNL) completed a GWAS investigation to determine if there are QTL associated with gape date, gape angle, and chemical hybridizing agent phytotoxicity. He identified 73 significant marker-trait associations for all assessed traits. The MTAs were located on all chromosomes except for 1D, 3D, and 4D. 20 MTA were detected for gape date, 33 MTA for gape score, and 20 MTA for CHA phytotoxicity. Based on 200 kb window around the significant SNPs, 111 candidate genes were identified using SnpEff for functional gene annotations including 34, 51, and 29 for gape date, gape score, and CHA damage, respectively. TraesCS4B02G242300, TraesCS4B02G242400, and TraesCS7D02G039500 genes were identified for both gape score and CHA phytotoxicity. Male parent traits such as plant height, anther extrusion, and lodging were evaluated in the biparental double haploid population generated from the cross Freeman x Camelot. The cultivar Freeman is an excellent anther extruder while Camelot is a poor anther extruder. However, both lines are homozygous Rht-B1b, therefore QTLs identified in this populations should not be associated with plant height. UNL Postdoc Dr. Sandeep Sakhale completed the analysis of this population and the manuscript will be submitted this fall. Briefly, anther extrusion was consistent across environments with moderate heritability despite genotype-by-environment interaction. Compared to the donor parent "Freeman", twenty-nine transgressive segregants consistently showed increased anther extrusion across environments. Three QTLs (QAe.unl-2B, QAe.unl-3A, and QAe.unl.5D) were identified for anther extrusion and were not associated with plant height. Of these QTLs, the QAe.unl-2B and QAe.unl.5D overlapped with previously reported QTLs within 35Mb and 100Mb windows. We recommend further investigation, validation, and implementation of these QTLs for selecting improved hybrid parents. Obj. 3. Three trials comprising 112 F1 wheat hybrids were grown for yield predictions in two mega environments in Texas (Blacklands and High Plains) to investigate the potential of using parental traits for predicting performance in a set of high and low-yielding hybrids. The Bushland location (High Plains) typically has lower spatial variability and has the highest reproducibility. However, we abandoned the 2022-2023 Bushland F1 hybrid trial due to extreme drought. We also abandoned the Pilot Point (Blacklands) trial due to extreme waterlogging conditions resulting from heavy rains after planting. We could harvest only the McGregor hybrid wheat trial (Blacklands) in 2023. Mr. FNU Abdullah, a Ph.D. student at TAMU, is currently analyzing this data. Mr. Abdullah also dedicates part of his effort to looking at root heterosis in a set of F1 hybrids and their parents. Technologies such as MRI and ground penetrating radar (GPR) are used to predict the various root traits. Three sets of crossing blocks were also established in Chillicothe, TX (2) and Lincoln, NE (1) in the Fall of 2022 to produce hybrid seeds for the 2023-2024 growing season trials. Obj. 4. We continue to make crosses and back crosses to incorporate CMS into multiple backgrounds. We are continuing our R-line development. At CIMMYT, four F2 populations were derived by crossing four recombinant inbred lines (RILs) carrying single or multiple Rf genes / QTL (1B, 5A, and 6B) with a standard CMS tester carrying T. timopheevii cytoplasm. The F2 plants- ranging from 255 - 456 from each population were evaluated for spike fertility by counting the seed set in each spike. Leaf tissues from all the F2 plants and their parents was collected and stored. A total of 43 KASP assays were designed within the 1B, 6B and 5A QTL region for further fine mapping and marker design/validation for breeding. The 43 KASP assays plus the markers originating from the initial QTL mapping study and some public markers related to the QTL on chromosome 1B (Rf3) were tested on multiple plants across the parent of the four mapping populations (Annex 1). Many KASP assays were monomorph. For the 1B QTL a total of 32 KASP assays were tested with five KASP assays showing polymorphism among the parents of POP1. For the 5A and 6B QTL, eight and seven KASP assays showed polymorphism across the populations carrying the QTL, respectively. DNA was extracted for all individuals in each F2 population (1577 individual plants). The polymorphic KASP assays were used to genotype the F2 individual in the respective population, with a few examples given in Figure 2. A total of 20 KASP assays were used across the populations. Segregating markers, although only a few were used for fine mapping the QTL. The seed set data that were previously evaluated were combined with the KASP assay data. The IciMapping software was used for mapping applying the default parameters. The QTL on chromosome 1B could be confirmed in POP1. One of the newly developed KASP assays were observed as one of the new flanking markers and the genomic regions of the QTL could be significantly narrowed, located between 18120649 - 20046556 Mbp on the physical position of the Chinese Spring reference sequence (IWGSC vs. 01). Similarly, the QTL was observed with a mayor effect, with a LOD score of 46, explaining 38% of the phenotypic variation of the trait in this population. The mapping for QTL 5A and 6B is still ongoing.

Publications

• Type: Journal Articles Status: Published Year Published: 2023 Citation: Garst, N., Belamkar, V., Easterly, A., Guttieri, M.J., Stoll, H., Ibrahim, A.M. and Baenziger, P.S., 2023. Evaluation of pollination traits important for hybrid wheat development in Great Plains germplasm. Crop Science. https://doi.org/10.1002/csc2.20926

Progress 06/01/21 to 05/31/22

Outputs
Target Audience:Our main stakeholders are small grain producers that can benefit from the improved grain yield and yield stability provide by hybrid wheat. Increased yield and stability has the potential to benefit the entire wheat value chain by providing end users such as milling and baking companies, livestock producers, and consumers by maintaining production while reducing input requirements and their requisite costs. We reach these stakeholders through annual field day presentations in Nebraska and Texas, meetings such as the Nebraska Crop Improvement Association Meeting or Wheat Quality Council, and we use Twitter and other media to share or research informally. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?1 M.S. student at UNL plans to graduate in December 2022 with a thesis on female floral characteristics. 1 post doc at UNL working on QTL mapping for anther extrusion. Both have had or will have the opportunity to present at conferences such as the Crop Science Society of America (Nichole, 2021), and the National Association of Plant Breeders (2 students). 2 UNL students working on hybrid related project graduated in May 2022. How have the results been disseminated to communities of interest?We are disseminating our results through scientific publications (including 2 in 2022) and germplasm under the relevant MTAs. Also, we have a regular meetings to discuss hybrid wheat with our advisory board and interested parties. What do you plan to do during the next reporting period to accomplish the goals?We will finish analysis for the hybrid yield trials harvested in 2021 that were developed to validate our genomic predictions for parent selection. We will complete phenotypic analysis for gape date and angle and CHA phytotoxicity and GWAS for these traits using cultivars previously planted in UNL crossing blocks. We will submit a manuscript for anther extrusion in the Freeman x Camelot mapping population. We will continue to collaborate with scientists in Germany and Iowa State University to develop better parental selection algorithms and hybrid predictions. 0.1We continue to make crosses and back crosses to incorporate CMS into multiple backgrounds. The SNPs tagged to known and potential novel restorer genes identified in the ongoing work will be further validated in newer backgrounds. We are continuing our Rline development in winter wheat.

Impacts
What was accomplished under these goals? Obj1: The 2021 trials for heterosis validation were harvested at three locations in Nebraska (254 F1 hybrids) and two locations in TX (180 F1 hybrids). Analysis is ongoing, however, preliminary results show that more hybrids outperform the commercial check cultivars under stress conditions compared to under ideal production conditions. For example, in Lincoln, NE, a high yield potential location, only 5 hybrids out-yielded the commercial checks compared to at Alliance, NE, a drought prone location, where 84 hybrids outyielded the top commercial check. 2021-2022 Trials: F1 Hybrid trials were planted to validate performance of previously predicted hybrids. The genotypes entered in the trials were mostly hybrids that had limited seed in previous years or those entered in trials that failed due to environmental hazards such as drought or hail. In Nebraska, three trials with 240 F1 hybrids were planted at Lincoln, North Platte, and Alliance, NE which represent three mega environments for wheat production in the state (Eastern, Central, and Panhandle). The trials were planted in augmented single rep designs. These hybrids were predicted to be high or low yielding and the harvested results will be used to validate our prediction models in summer 2022. The Alliance trial was lost to hail in May 2022, but the other two locations will be harvested. In Texas three trials with 118-136 F1 hybrids were grown yield performance in 2 mega environments (Blacklands and Bushland). The goal was to test high and low yielding hybrids and investigate whether the predictions and parental traitscan help predict the high and low-yielding set. The Bushland location has lower spatial variation than the other environments over the years and had the highest reproducibility (in terms of hybrid performance). Bushland is critical to help investigate the questions as thereis significant variability or incomplete datasets in other environments.Data will be analyzed soon by Kyle Parker, a PhD student in the TAMU Small Grains Program working on genomic prediction. Obj2: The female lines that were planted in the new hybrid crossing blocks will be evaluated for female gape date and gape angle (the two key female traits) in 2021 and 2022. M.S. student Juan Jimenez (UNL) has compiled female trait data from previous years crossing blocks for use in a GWAS investigation to determine if there are QTL associated with gape date, gape angle, and chemical hybridizing agent phytotoxicity. A replicated panel of all cultivars used in these crossing block (with available seed) was planted in Fall 2021 and will be used for the GWAS study. Male parent traits such as plant height, anther extrusion, and lodging were evaluated in the biparental double haploid population generated from the cross Freeman x Camelot. The cultivar Freeman is an excellent anther extruder while Camelot is a poor anther extruder. Improved anther extrusion will improve the seed yield of hybrid wheat crossing blocks. M.S. student Emre Karahan (UNL) evaluated the male phenotypes and determined that in this population anther extrusion is not related to plant height. QTL mapping will be completed in 2022 and a manuscript is in preparation. Obj3:We planted two new hybrid crossing blocks (one in Texas and one in Nebraska) in Fall 2021. These crossing blocks will produce F1 seed for evaluation of heterotic group predictions made in late 2020. The evaluation of these hybrids will be completed in summer 2023. Analysis will be completed by UNL post-doc Dr. Sandeep Sakhale. Obj4:We continue to make crosses and back crosses to incorporate CMS into multiple backgrounds. We are continuing our R-line development. Our collaborators at CIMMYT continue to make progress on restorer gene mapping populations. In FY21, these populations were advanced several generations. They will be genotyped in FY 22.

Publications

• Type: Journal Articles Status: Published Year Published: 2022 Citation: Sade, Betul, Amir MH Ibrahim, Nithya Subramanian, Jackie Rudd, Shuyu Liu, Gigi Opena, and Stephen Baenziger. "Assessment of floral characteristics for hybrid wheat (Triticum aestivum L.) production in Texas." Agrosystems, Geosciences & Environment 5, no. 1 (2022): e20228. https://acsess.onlinelibrary.wiley.com/doi/full/10.1002/agg2.20228
• Type: Journal Articles Status: Published Year Published: 2022 Citation: Basnet, Bhoja Raj, Susanne Dreisigacker, Arun K. Joshi, Khondoker Abdul Mottaleb, Anil Adhikari, Manish K. Vishwakarma, Pradeep Bhati, Uttam Kumar, Jagdish Chaurasiya, and Umesh Rosyara. "Status and Prospects of Hybrid Wheat: A Brief Update." In New Horizons in Wheat and Barley Research, pp. 637-679. Springer, Singapore, 2022. https://link.springer.com/chapter/10.1007/978-981-16-4449-8_24
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A.M.H. Ibrahim, J.C. Rudd, P. Stephen Baenziger, Jean?Benoit Sarazin. 2020. Estimation of heterosis and combining abilities of U.S. winter wheat germplasm for hybrid development in Texas. Crop Sci. 60 (2), 788-803. doi.org/10.1002/csc2.20020.

Progress 06/01/20 to 05/31/21

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 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?Travel has been greatly restriticted due to covid-19 and we had difficulties filling the gradaute assistantship due the first student was from Pakistan (had to withdraw due to family issues) and the new student only recently joined our program due to delays in getting his visa. However, one advantage of the covid-19 era is that students and faculty are able to attend numerous meetings at a reduced cost (e.g. the Crop Science Society of Amreica (3 faculty), the Scab Forum (2 related students and 1 faculty member), and the National Association of Plant Breeders (4 related students and 2 faculty members). How have the results been disseminated to communities of interest?We are desseminating our results through scientific publications (1) and germpaslm under the CIMMYT SMTA. Also, we have an annual meeting every year to discuss hybrid wheat with our advisory board and interested parties. What do you plan to do during the next reporting period to accomplish the goals?The hybrid yield trials planted to determine heterosis reproducibility were harvested in 2020, and the phenotypic analysis is completed. We will be investigating the heterosis reproducibility next. The hybrid yield trialsharvested in 2021 will validate our approaches to design crosses (for high-yield, for instance) using genomic predictions for target environments. We will evaluate the female lines in the crossing block for gape date and angle and the male lines for anthesis date, anther extrusion, plant height, and pollination duration. The male traits will also be evaluated in breeding lines in elite yield trials grown in the varietal breeding program. The 2020 crossing blocks in NE and TX which will be sprayed and harvested in 2021 contain most of the crosses made in 2019-2020 (to test hybrids for the second year), a small number of crosses grow in multiple plots to make elite hybrids for relatively larger scale testing, and in NE an additional 60-100 crosses based on high-GCA lines and heterotic groups identified using the annealing algorithm developed by our German Collaborators were grown. We continue to make crosses and back crosses to incorporate CMS into multiple backgrounds. The SNPs tagged to known and potential novel restorergenes identified in the ongoing work will be further validated in newer backgrounds. We are continuing our R-line development in winter wheat.

Impacts
What was accomplished under these goals? Obj.1. Validate heterosis from previously made and predicted wheat hybrids in replicated trials. We planted our next set of hybrid wheat yield trials to validate heterosis at three locations in Nebraska and three locations in TX. Three or two (where there was limited seed) replicate alpha lattice experimental designs were used for all yield trials. Obj. 2.Continue male and female (main emphasis) parent line evaluation for characteristics needed to develop experimental and commercial wheat hybrids in a cost-efficient manner. The female lines that were planted in the new hybrid crossing blocks will be evaluated for female gape date and gape angle (the two key female traits) in May, 2021. All of the male lines and many additonal male lines were planted and will be evaluated in May, 2021. Obj. 3.Develop heterotic groups or patterns and test multiple mating designs for wheat hybrids. We planted two new hybrid crossing blocks (one in Texas and one in Nebraska). Obj. 4.Continue cytoplasmic male sterility (CMS) line development and identify and validate restorer genes for wheat hybrids. We continue to make crosses and back crosses to incorporate CMS into multiple backgrounds. We are continuing our R-line development. The spring wheat germplasm from CIMMYT is to the point where they can be shared.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Adhikari, A., B. R. Basnet, J. Crossa, S. Dreisigacker, F. Camarillo, P. K. Bhati, D. Jarquin, Y. Manes, and A. Ibrahim. 2020 Genome-wide association mapping and genomic prediction of anther extrusion in CIMMYT hybrid wheat breeding program via modeling pedigree, genomic relationship and the interaction with environment. Front. Genet: doi: 10.3389/fgene.2020.586687