Project Progress in FY2012
Developed two genetic mapping populations for seed yield from prominent ancestors of northern and southern USA varieties, using the cross Essex - Williams 82: one population currently designated "ExW-1536a" with approximately 300 F5-derived recombinant inbred lines (RILs) for 1536 SNP assay another population currently designated "ExW-50Ka", with approximately 1,000 RIL for >50,000 SNP assay.
In population ExW-1536a, the Golden Gate assay of the universal soybean linkage panel using 1536 SNPs ExW-1536a identified 480 polymorphic SNP markers across the genome.
Yield QTL have been detected using population ExW-1536a on six chromosomes (chromosomes 5, 10, 12, 13, 15, and 19) from replicated field trials grown by soybean breeders at Arkansas, Illinois, and Tennessee.
Marker assisted selections using population ExW-1536a for RILs carrying favorable versus unfavorable SNP allele types were field tested for effects on seed yield.
In population ExW-50Ka, over 50,000 SNPs were screened by USDA identifying >17,000 polymorphic SNP markers across the genome of 20 chromosomes, and will play a key role in creating a new USDA consensus SNP map of the soybean genome.
The high level of SNP polymorphism provided a finely mapped average distance between markers of 0.2 centimorgans (cM) in our recent version of mapped genome, abundantly tighter than any genetic population/SNP analysis we have previously worked with.
Field data for population ExW-50Ka has been acquired from replicated field trials grown by soybean breeders at Illinois, Ohio, Missouri, North Carolina, and Tennessee.
Data analyses have begun on the approximately 15 million DNA data points of population ExW-50Ka in association with effects on measured seed yield.