Location: Crop Production and Pest Control Research
Project Number: 5020-21000-008-000-D
Project Type: In-House Appropriated
Start Date: May 9, 2018
End Date: May 8, 2023
Objective:
Objective 1: Identify genetic loci involved in seed oil, protein, and carbohydrate content using forward and reverse genetic approaches, and create genetic combinations that serve as new variability for selection in breeding programs.
Subobjective 1A: Identification of genes implicated in control of seed protein/oil levels.
Subobjective 1B: Alteration of carbohydrate partitioning in soybean seeds.
Subobjective 1C: Combining genes identified by this project to form a basis for improved soybean germplasm.
Objective 2: Evaluate newly identified sources of resistance against Phytophthora sojae, identify candidate Avr gene(s) in the pathogen that are recognized by the new resistance, and design strategies to maintain resistance.
Objective 3: Characterize population structure of Fusarium virguliforme, determine the role of root endophyte community in SDS (soybean Sudden Death Syndrome) resistance, identify key endophytes that can be used for development of new control strategies, and create a SDS genome-wide molecular marker database as a resource for research.
Objective 4: Construct, coordinate, and publish the results of a relevant regional and national variety testing program for soybean that provides timely phenotypic information useful for selection.
Approach:
Objective 1: Genes regulating carbohydrate, protein, and fatty acid levels of soybean seeds will be identified using a combination of forward and reverse genetic approaches. Mutants will be evaluated by NIR, GC, and HPLC analysis for multiple aspects of seed composition. Conventional and sequence-enabled mapping techniques will be used to determine gene positions. qRT-PCR will be used to measure the expression of candidate genes during seed development. The best candidate genes will be validated through transformation assays to determine gene impact on seed phenotype.
Objective 2: The performance of resistance genes, including several recently identified, will be evaluated against a large collection of Phytophthora sojae isolates. The best gene pyramiding combination will be recommended for soybean breeding efforts. Genomes and transcriptomes of a subset of isolates will be sequenced to determine how P. sojae evades gene-mediated host resistance, and to identify candidates for uncharacterized Avr genes.
Objective 3: A genome-wide informative microsatellite marker database will be constructed for Fusarium virguliforme using a comparative genomics approach. Identified microsatellite markers will be used to investigate global population structure of F. virguliforme. Prokaryotic and eukaryotic root endobiome of soybean lines susceptible or highly resistant to sudden death syndrome will be characterized using culture and high-throughput sequencing approaches. Endophytic groups associated with SDS resistance will be identified.
Objective 4: Public soybean breeders submit their soybean breeding lines for evaluation of agronomic performance, disease resistance and quality traits. Entries are separated by maturity group and assigned to either the ‘Preliminary Tests’ or the ‘Uniform Tests’. Seeds of each entry, along with those of the standard reference varieties, are packaged and distributed to collaborators throughout the U.S. and Canada for evaluation. In addition, entries will be evaluated at multiple locations in Indiana. Harvested seeds will also be tested for quality traits. Collaborators submit performance data from their locations to ARS after harvest. This data is compiled and analyzed by this research group following established protocols. The results will be published in an annual report book and online.
