Progress 03/01/18 to 02/28/23
Outputs
Target Audience:Students, researchers, growers, and biofuel industry. Changes/Problems:The COVID impacted the timely processing of tissue samples, which extended the planned duration of a project and the RNA analysis. What opportunities for training and professional development has the project provided?Graduate and undergraduate students were trained in plant breeding and genetics. A postdoctoral research associate was provided a week-long hands-on training on molecular data analysis at the USDA, Berkeley, on February 24-28, 2020. The training involved different bioinformatic tools for processing genomic sequence data and workflow in generating molecular markers. In addition, the postdoc obtained a week-long virtual workshop on RNA sequencing at the University of Tennessee, Knoxville, on January 18-21, 2022. The training helped her understand sequence data processing and visualize gene expression patterns across samples. Also, the project helped her to enhance her professional skills by providing opportunities to interact with global leaders through participating and presenting at the ASA-CSSA-SSA International annual meetings in 2020, 2021, and 2022. How have the results been disseminated to communities of interest?The results of the study were disseminated through presentations and publications. One oral and three posters were presented at 2020, 2021, and 2022 ASA-CSSA-SSA International annual meetings. A manuscript was published in the "Crop Science" journal on August 11, 2021 (https://doi.org/10.1002/csc2.20618). The switchgrass picture highlighting the article was featured on the cover page of the journal on November 23, 2021 (https://acsess.onlinelibrary.wiley.com/toc/14350653/2021/61/6). Undergraduate and graduate students were educated and trained in the scientific method and in conventional and molecular breeding techniques. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Breeding of perennial crops like switchgrass through conventional breeding techniques is slow due to its requirement of four or five years to complete a single selection cycle and requiring several years of field testing. The whole genome sequence of switchgrass has led to tremendous opportunities to explore its genetic potential. Using molecular and computational tools helps to understand the location of genes (markers) through their association with traits of interest. Hence, the selection of a particular trait can be enhanced through marker-based selection. The identification of markers closely associated with biomass yield and bioenergy traits, including cellulosic ethanol, will be a valuable tool to breeders for early and effective selection of the traits. The introgression of these markers in breeding will expedite selection of the best Alamo and Kanlow hybrids that are highly productive under lower fertilizer input environments. High biomass yield per unit area with reduced cost of fertilizer applications will provide greater profit to switchgrass producers and contribute better sustainability to biomass feedstock production. Lowering the cost of producing switchgrass can also benefit industrial biofuel producers and energy consumers. Furthermore, switchgrass is one of the best crops for carbon sequestration, which offers several environmental benefits. Objective 1: To identify candidate gene-regions associated with biomass yield heterosis This study demonstrated biomass yield heterosis between Alamo and Kanlow hybrid populations. In addition, the populations exhibited differences in bioenergy traits. To identify genomic regions associated with biomass yield and bioenergy traits, quantitative trait loci (QTL) mapping was performed within each and across environments using a composite interval mapping based on a Haley-Knott regression method. The logarithm of the odds (LOD) threshold for each trait was calculated based on 1000 permutations. Eleven QTL peaks for biomass yield, 15 QTL peaks for plant height, and 10 QTL peaks for clonal mass were identified on several chromosomes (LOD score>3, P≤0.05). The major QTL for biomass yield, plant height, and clonal mass resided on chromosomes 8N, 6N, and 8K explaining phenotypic variations of 5.6, 5.1, and 6.6%, respectively. A total of 90 QTL peaks for bioenergy traits, including cellulose, hemicellulose, ethanol, ash, esters, ether, lignin, glucose, and sugars, were identified through this study (LOD score>3, P≤0.05). Molecular markers with a large effect on biomass yield and bioenergy traits will be incorporated into switchgrass breeding, which could accelerate the process of heterotic pool development and consequent development of hybrid cultivars. Objective 2: To assess variation in gene expression in high and low biomass-yielding genotypes A total of 160 samples derived from two different growth stages, spring re-growth and pre-heading, were evaluated for RNA expression analysis. The sequencing libraries were constructed using TruSeq (IlluminaTM) RNA library construction procedures. Single-end reads of 100 bp were generated on an Illumina HiSeq4000. RNAseq resulted in over 20M reads per sample, which should provide enough coverage to draw inferences. The average sample size was 6038 Mbases, mean quality score of 35, and contained 89.8% bases. RNA sequence quality was assessed using bioinformatics tools (e.g., FastQC, MultiQC). All adapter sequences were trimmed using "Trimmomatic," The sequence with the 'Quality score (Q) less than 30' was filtered out. The trimmed sequences were aligned with switchgrass reference genome 5.1. Differential gene expression analysis across hybrid populations at different growth stages is currently ongoing. Objective 3: To perform field testing of experimental hybrids Seed of two polycross nurseries were harvested from the ETREC Holston unit. Approximately, 8.5 and 7.0 lb seeds harvested for 12A-227 × 12K-268 and TN13006-04 (A) × TN13009-8 (K). The biomass yield performance of experimental hybrids and their reciprocals were evaluated along with their parents and commercial checks in seed drill and simulated sward plantings at both ETREC and PREC. Syn#2 outperformed checks by 29% in the seed drill. Whereas, in simulated sward planting, biomass yield of the hybrid (12K-268 ×12A-227) outperformed the checks by 17%. The results demonstrate that the hybrids exhibited differential biomass yield potentials under seed-drill and simulated sward plantings when varying plant density was used. The findings of Syn#2 performing best under seed drill and the experimental hybrid, 12K-268 ×12A-227, performing well under simulated sward plantings indicated that planting method also plays an essential role in the hybrid performance. Therefore, it is imperative to understand the choice of the best planting methods for future testing of hybrids. Objective 4: To train graduate and undergraduate students in breeding Six undergraduate students, one graduate student, and one postdoctoral research associate were trained on breeding principles and procedures, field data collection, and greenhouse plant management techniques. The trained students and the research associate assisted in lab, field, and greenhouse data collection, biomass harvesting, and tissue collection and processing for biomass compositions and RNA expression analyses. Issue/problems With the possibility of using switchgrass as bioenergy crops to mitigate the fuel crisis, this project was anticipated with the importance of developing switchgrass varieties that can perform well in the low nutrient environments. However, switchgrass breeding, propagation, and phenotypic field evaluation are challenging. Switchgrass has some level of seed dormancy leading to poor and non-uniform seed germination. In the seed-drill plot of this study, seed germination on some plots was <30%. We terminated the whole plots, and plots were re-sown in the next planting season. Before re-sowing the plots, the germination of each genotype was tested, and the seed sowing density of those genotypes with poor seed germination was increased based on the germination results. In addition, plant growth during spring was a challenge in both drill and simulated plots due to the weed pressure. This led to high plot-to-plot variation in plant stands. In order to avoid the higher competition of switchgrass with weeds, the plots were sprayed with pre-and-post-emergence herbicides. Many switchgrass breeding programs rely on conventional techniques that take a long time to generate a new variety. The use of molecular markers in the breeding helps focus on those plants with a trait of interest and discard undesirable plants at an early selection cycle. Through this, it saves both time and inputs requiring selection and testing. In addition, the efficacy of selection of a trait of interest is increased by imposing selection only on the desirable trait. Molecular markers with a large effect on biomass yield identified through this study will be incorporated into switchgrass breeding. It would help in efficient selection of desirable traits and could accelerate the process of heterotic pool development and consequent development of hybrid cultivars. Switchgrass is a cross-pollinated and self-incompatible species thus hybrid seed must to be produced in an isolated field to avoid cross-contamination. In this study, we established two seed production blocks that were separated by adequate distance to avoid cross contamination. In each production block, two parental genotypes were planted in alternate rows due to their inability to set seeds by self-pollination. Due to self-incompatibility, hybrid seed were harvested from each parental row and represented reciprocal crosses.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2023
Citation:
Mapping quantitative trait loci for biomass yield and yield-related traits in lowland switchgrass (Panicum virgatum L.) hybrid populations (submitted to G3).
- Type:
Journal Articles
Status:
Submitted
Year Published:
2023
Citation:
Genetic variation for bioenergy traits within and among lowland switchgrass (Panicum virgatum L.) crosses (submitted to Biomass and Bioenergy).
- Type:
Journal Articles
Status:
Other
Year Published:
2023
Citation:
Mapping quantitative trait loci for bioenergy traits in lowland switchgrass (Panicum virgatum L.) hybrid populations (in preparation).
- Type:
Journal Articles
Status:
Other
Year Published:
2023
Citation:
Identification of genetic variation and mapping quantitative trait loci for forage quality traits within and among switchgrss (Panicum virgatum L.) hybrid populations (in preparation).
|
Progress 03/01/21 to 02/28/22
Outputs
Target Audience:Students, researchers, growers, and biofuel industry. Changes/Problems:Due to COVID-19, the visitors' access to the USDA collaborator facility in CA has been limited. It has affected the hands-on training of the postdoctoral research associate on RNA expression data analysis at the USDA, Berkley, CA, in 2021. The training was accomplished virtually. The COVID also has impacted the timely processing of tissue samples and RNA analysis which has extended the planned duration of a project. What opportunities for training and professional development has the project provided?A postdoctoral research associate obtained a week-long virtual workshop on RNA sequencing at the University of Tennessee, Knoxville, on January 18-21, 2022. The training helped the research associate to understand different bioinformatic tools behind sequence data processing, workflow on data analysis, and visualizing gene expression patterns across samples. How have the results been disseminated to communities of interest?The results of the study were disseminated through presentations and publications. An oral presentation was made at the 2021 ASA-CSSA-SSA International annual meeting, Salt Lake City, UT. A manuscript was published in the 'Crop Science' journal on August 11, 2021 (https://doi.org/10.1002/csc2.20618). The switchgrass picture highlighting the article was featured on the cover page of the journal on November 23, 2021 (https://acsess.onlinelibrary.wiley.com/toc/14350653/2021/61/6). What do you plan to do during the next reporting period to accomplish the goals?QTL mapping and gene expression analysis will be continued. Draft manuscripts on QTL mapping and biomass composition traits evaluated on the hybrids will be submitted to appropriate scientific journals. Biomass yield will be collected from seed drill and transplanted trials. Hybrid seeds will be harvested from the polycross nurseries.
Impacts
What was accomplished under these goals?
Selection of switchgrass through conventional breeding is slow due to its perennial growth habit and its requirement of four to five years to complete a single selection cycle. The whole genome sequence of switchgrass has led to tremendous opportunities to explore its genetic potential and target the genomic regions responsible for increasing biomass yield and improving production under biotic and abiotic stress environments. The proposed project aims at identifying genes conferring hybrid vigor for biomass yield. We hypothesize that Alamo and Kanlow populations, representing different gene pools, presumably carry different sets of favorable genes which are complementary to each other. Recently completed results also demonstrated the potential for exploiting biomass heterosis between the two populations in order to increase biomass productivity. We developed biparental crosses to map chromosomal regions associated with biomass yield. The molecular markers associated with biomass yield loci will be incorporated into switchgrass breeding activities which should accelerate the process of heterotic pool development and consequent development of hybrid cultivars. In addition to this, we will examine sequence variation and differential expression within transcribed regions of genes in both low and high yielding genotypes to identify candidate genes residing within QTL regions that may contribute to yield.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Shrestha, Surya & Bhandari, Hem & Allen, Fred & Tobias, Christian & Nayak, Santosh & Goddard, Ken & Senseman, Scott. (2021). Heterosis for biomass yield and other traits in alamo � kanlow switchgrass populations. Crop Science. 61. 10.1002/csc2.20618.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
An oral presentation was made on Heterosis and QTL mapping for biomass yield and other traits in switchgrass (Panicum virgatum L.) at the ASA-CSSA-SSA International annual meeting, November 07, 2021, Salt Lake City, UT.
|
Progress 03/01/20 to 02/28/21
Outputs
Target Audience:Students, researchers, growers, biofuel industry Changes/Problems:Ten seed drill plots at ETREC and all plots at PREC were re-seeded in May (ETREC) and June (PREC) 2020. These plots were re-seeded because of poor plant emergence. In addition to this, road expansion and other constructions near the vicinity of simulated-sward plots at ETREC led to relocation of two plots on the other side of the same field. What opportunities for training and professional development has the project provided?A postdoctoral associate was provided a week long hands-on training on molecular data analysis at Dr. Christian Tobias laboratory USDA, Berkeley, in February 24-28, 2020. The training involved different bioinformatic tools used in processing genomic sequence data and workflow in generating molecular markers. How have the results been disseminated to communities of interest?The results of the study was disseminated through presentations and publications. A poster entitled as 'Heterosis for biomass yield in 'Alamo x Kanlow' switchgrass populations' was presented at a virtual annual meeting of ASA-CSSA-SSA held in November 9-30, 2020. A draft of manuscript on 'Heterosis for biomass yield and other traits in 'Alamo' x 'Kanlow' switchgrass populations' is being prepared, for submission to the 'Crop Science' journal in the Spring 2021. What do you plan to do during the next reporting period to accomplish the goals?Biomass yield will be collected from hybrid populations and seed-drill and transplanted trials. Hybrid seed will be harvested from the polycross nurseries. Gene expression analysis will be carried out at the QTL regions.
Impacts
What was accomplished under these goals?
Objective 1: To identify candidate gene-regions associated with biomass yield heterosis Ten populations derived from a biparental cross of Alamo x Kanlow were screened in the field for biomass yield and other phenotypic traits, including plant height and clonal mass. The number of F1 progenies in the population varied from 30 to 96 (Table 1). Eight of the crosses produced enough F1 progenies to plant at two field locations while two populations only produced enough plants to establish at a single location. The F1 progenies of each of the eight crosses were divided into two subsets, each with approximately equal numbers of progenies, and were planted at the University of Tennessee, the East Tennessee Research and Education Center (ETREC), Knoxville and Plateau Research and Education Center (PREC), Crossville, TN. The experiment was conducted in a randomized complete block design with two replications per location and plots were planted in June (PREC) and July (ETREC) 2018. The single row plots consisted of six plants spaced 30 cm apart within the row and 122 cm spacing between rows. Biomass was harvested on November 2019 and 2020 at a height of approximately 20 cm. Both mid parent heterosis (MPH) and high parent heterosis (HPH) were computed for biomass yield. Plant height was measured from the base of the plant to the top of the panicle. Clonal mass was scored on a scale of 1 to 5, where a score of 1 indicated a low number of stems and a small diameter of the clone spread. Biomass yield of the crosses at PREC site was 41% higher than ETREC (Table 2). The crosses differed significantly for both MPH and HPH (P<0.05), and demonstrated 2 to 125% MPH and -20 to 108% HPH for biomass yield across the environments (Table 3). The cross, 12A-221 x 12K-216, had a higher MPH and HPH for biomass yield than other crosses evaluated at both locations. Biomass yield was indirectly assessed by plant height and clonal mass. A stronger association was found between biomass yield and clonal mass at PREC (R2 = 0.29 to 0.40) than at ETREC (R2 = 0.15 to 0.23) (P<0.001) (Figure 1). Also, the association between biomass yield and plant height was higher at PREC (R2 = 0.10 to 0.32) than at ETREC (R2 = 0.06 to 0.11) (P<0.001). To identify genomic regions associated with biomass yield, DNA was extracted from leaves of populations using the CTAB procedure. The extracted DNA was sent to co-PI Tobias' laboratory at the USDA-Western Regional Research Center for genotyping. Genotyping by sequencing has been performed on a total of 951 lines and we obtained 4.3 ± 1.8 M reads per sample. The quality of these sequences showed that 94.4% of the bases were at or above Q30. Reads were mapped to version 5.0 of the switchgrass reference genome and nucleotide polymorphisms (NP) were called. A total of 137,909 markers were developed. A consensus map was produced with Lep-Map3 software (https://doi.org/10.1093/bioinformatics/btx494). Based on segregation analysis, populations 7 and 8 were consolidated as were populations 9 and 10. The current version of the consensus map was created from 648 individuals. Eighteen linkage groups (LG) were formed at a LOD value of 16. NP were then ordered and NP parental phase was estimated using the Lep-Map3 likelihood maximization method. The map summary is shown in Table 4. The map is in very good agreement with published map lengths for switchgrass (https://doi.org/10.3835/plantgenome2014.10.0065) with an overall length of 1939 cM. Map quality was assessed relative to the switchgrass genome by Spearman's ranked correlation (rs) of marker order which was greater than 0.98 for all linkage groups. Marker-based estimates of heritability m) for plant height, biomass yield and clonal mass after harvest were calculated on pairwise genetic relatedness and trait data from 2019 and 2020 (described above) using environment and year as covariates (https://pubmed.ncbi.nlm.nih.gov/20562875/, https://doi.org/10.1534/genetics.114.167916). The 95% confidence intervals for m for biomass (0.43, 0.54), plant height (0.39 0.49), and clonal mass (0.50, 0.60) were in the moderate range of heritabilities. QTL detection for plant height, biomass, and clonal mass traits has so far used a 2-stage analysis on the trait best-linear unbiased predictions (BLUP). Subsequent genome scans based on a single QTL model using Haley-Knott regression were performed in r/qtl (www.rqtl.org). Significant LOD peaks that exceeded the genome-wide significance threshold (α=0.05) are shown in Table 5. In population 7_8 QTL for both biomass and clonal mass BLUP are detected on linkage group Chr03K, within 10 cM of one another (Figure 2). This is interesting as the traits were positively correlated with a Pearson product-moment correlation of 0.604 (t = 35.639, df = 2208, P ≤ 2.2 x10-16). These types of correlated traits are useful for breeding purposes providing useful information that can be used to improve the accuracy of selection. Currently we are evaluating methods to perform further QTL analysis incorporating site-year data into a single stage analysis, taking into consideration polygenic effects, and also taking advantage of all full-sib and half-sib relationships to increase the accuracy of QTL analysis. Objective 2: To assess variation in gene expression in high and low biomass-yielding genotypes We will start to work on the Objective 2 activities in the Spring 2021. The tissue samples will be collected at two different growth stages, spring regrowth and heading, respectively. These growth stages are selected because the expression of trait can be easily differentiated at these stages. The crosses at which QTL were identified (in objective 1) will be targeted for gene expression analysis. Objective 3: To perform field testing of experimental hybrids Two sets of Alamo x Kanlow genotypic crosses with superior biomass performance were planted in the Fall 2018 to produce hybrid seeds. The two polycross nurseries, TN13009-8 X TN13006-04 and 12A227 X 12K-268, were planted in two different areas at ETREC Holston unit to avoid cross pollination between these populations. Seed of those populations were harvested in 2018, 2019 and 2020. Biomass yield performance of the two experimental hybrids (12A-227 X 12K-268 and TN13006-04 X TN13009-08) and their recriprocals were tested at two locations - ETREC and PREC, along with their parents and other commercial checks. The test was planted in 2019 using two planting methods - seed drill and simulated sward. In the seed drill, each plot was planted with seven drill-rows, four replications, with a 18 cm spacing between the rows and at seed rate of 4 kg ha-1. In the simulated sward, seedlings established through clonal propagation were planted in two replications with a plant spacing of 30 cm. The biomass was harvested on November 2020. Due to <40% of emergence of 'Cimmarron' and 'Syn2' at PREC, no biomass yield data was recorded in the seed drill at PREC (Figure 3). Mean biomass yield of 12K-268 X 12A-227 was higher than other experimentals and checks in both seed drill and simulated plantings in the mean environment across the locations. Objective 4: To train graduate and undergraduate students in breeding One PhD student was awarded a doctoral degree in plant breeding and genetics in the Fall 2019. One postdoctoral research associate was hired in the Fall 2019 to complete research goals of the project. Two undergraduate students are trained on plant breeding and lab techniques. The students assisted on data collection and biomass harvesting procedures.
Publications
|
Progress 03/01/19 to 02/29/20
Outputs
(N/A)
Impacts
What was accomplished under these goals?
Objective 1: To identify candidate gene-regions associated with biomass yield heterosis Seven Alamo x Kanlow biparental crosses (C01, C02, C03, CO4, C05, C08 and C09) were generated in the field. The number of F1 progenies in the population varied from 60 to 96. The number of progenies of each cross were divided into two subsets. Each subset contained about equal numbers of progenies and were planted at two field environments, one at the East Tennessee Research and Education Center (ETREC), Knoxville, TN and the other at the Plateau Research and Education Center (PREC), Crossville, TN. The experiment was conducted in a randomized complete block design with two replications per location and plots were planted in June (Crossville) and July (Knoxville) 2018. Biomass was harvested at the end of November, 2019. Biomass yield heterosis was identified in F1 progenies (Fig 1). The F1 progenies of each biparental cross were significantly different for biomass yield at studied environments (P<0.05). Parents of cross populations were analyzed for biomass composition, including forage quality and ethanol traits. Several biomass composition traits exhibited genotypic variations (P<0.05) at Knoxville and Crossville (Table 1). Alamo and Kanlow heterotic pools were planted in pots in the ETREC and South greenhouses at Knoxville. Alamo pool is comprised of 15 genotypes and Kanlow pool is comprised of 17 genotypes. Those genotypes were selected based on superior performance of Alamo x Kanlow hybrid evaluations. Seeds were harvested in bulk from these heterotic pools in 2018 and 2019. To identify genomic regions associated with biomass yield, DNA was extracted from leaves of cross populations using the CTAB procedure. The extracted DNA was sent to Dr. Tobias' laboratory at the USDA- Western Regional Research Center for genotyping. Genotyping by sequencing has been performed on a total of 951 lines and we obtained 4.3 ± 1.8 M reads per sample. The quality of these sequences showed that 94.4% of the bases were at or above Q30. Data analyses are ongoing to map the reads back to the genome and identify SNPs segregating in the populations. Objective 2: To assess variation in gene expression in high and low biomass-yielding genotypes We will focus on the Objective 2 activities in the Spring 2021 after we accomplish project activities of Objective 1. Objective 3: To perform field testing of experimental hybrids Two sets of Alamo x Kanlow genotypic crosses with superior biomass performance were planted in the Fall 2018 to produce hybrid seeds. The two polycross nurseries were planted in two different areas at ETREC Holston unit maintaining an isolation distance to avoid cross pollination between these populations. Parental clones of these crosses, TN13009-8 X TN13006-04 and 12A227 X 12K-268, were propagated to produce 100 ramets of each parent. Seed of those populations were harvested in 2018 and 2019. Field performance of the two experimental hybrids was tested at two locations; ETREC and PREC. Those hybrids were planted along with their parents, Alamo and Kanlow, and with other commercial checks to compare biomass yield. The experiment was conducted in field trials with four replications per location. The test was planted in 2019 and two planting methods, drilled seed and simulated sward using ramets, were used. In the drilled seed, each plot was planted with seven drill-rows, with 18 cm row-row spacing and with the seed rate of 4 kg per ha. In the simulated sward, seedlings established through clonal propagation were planted with a plant spacing of 30 cm. Objective 4: To train graduate and undergraduate students in breeding One PhD student was awarded a doctoral degree in plant breeding and genetics in Fall, 2019. Two undergraduate students were trained on plant breeding and lab techniques. One postdoctoral research associate was hired in the Fall, 2019 to complete research goals of the project.
Publications
|
Progress 03/01/18 to 02/28/19
Outputs
Target Audience:Two undergraduate students, Sean Fuller and Ronald Moore have been trained infield experimentation and in-vitro propagation technique.Ronald Moore already joined graduate program in plant breeding. Sean Fuller is continuing his training. ResearchAssociate, Santosh Nayak is working towardshis pursuing his Ph.D. degree. Changes/Problems:Project is progressing as planned. No major changes in the project. What opportunities for training and professional development has the project provided?The project requiring rapid propagation of plant materials, and intensive plant care in the greenhsueofferedatremendous opportunity for training undergraduate students. Several other undergraduate studentswere also involved in the plant material preparation, greenhosue plant care and field planting using scientific methodologies. The field-planted mapping population was actually utilized as an instructional material for Introductory Plant Breeding Course.Twelvestudents actuallytook phenotypic data and learned data analysis and scientific reporting techniques. The project has also offered an opportunity to Santosh Nayak, Research Associate in the project to pursue his Ph.D. in Plant Breeding and Genetics. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?Objective 1To identify candidate gene-regions associated with biomass yield heterosis Phenotyping of the mapping population will be initiated during the next reporting cycle. DNA isolation of the mapping population will be completedand the DNA library will be constructed. Genotyping of the mapping populationwill be initiated. Objective 2: To be started in 2021 Objective 3 Test of field performance of experimental hybrids Seed is available for two superior Alamo x Kanlow hybrids for field testing.We will plant hybrid performance evaluation nursery in the field in two locations. The nursery will be planted in both drill-plots and and simulated-sward. A Ph.D. student or a postdoctoral fellow will be hired during the next cycle. The incumbent will be trained in conventional breeding methods and genomics analysis. We will continue training undergraduate students.
Impacts
What was accomplished under these goals?
Following accomplishements were made towards achieving the project objectives Objective 1: To identify candidate gene-regions associated with biomass yield heterosis The mapping population comprising of 780 genotypes was developed using remnant seed of nine Alamo x Kanlow biparental crosses that were previously selected based on superior hybrid performance. The population including their clonal parents has been sucessfully established in two field sites, Crossville and Knoxville, TN. Twelve clones of each genotype, six clones per plot, were planted. Leaf-tissues from all the genotypes of mapping population were collected for genomic analysis. DNA isolation and library construction is in progress. Objective 2: To be started in 2021 Objective 3 Test of field performance of experimental hybrids Parental clones of two previously selected Alamo x Kanlow hybrids were propagated to make 100 ramets each. Alamo and Kanlow clonal parents of each hybrid were planted in a crossing block using in 3' x 3' plant-spacing, and 20 rows x 10 plants plot.Alamo and Kanlow ramets were planted in alternate rows of 10 plants. The seed was harvested in bulk, and cleaning is in progress. Objective 4 Training of graduate and undergraduate students Two undergraduate students, Sean Fuller, and Ronald Moore have been trained. The two students were trained inmethodsof field experimentation, plant care in the greenhosue and in-vitro propagation technique and DNA isolation techniques for switchgrass. Ronald Moore already joind graduate program in Plant Breeding. Sean Fuller is still continuing in the project. Research Associate, Santosh Nayak is being trained on Advanced Plant Breeding and Genetics.
Publications
|
|