Identification of Genomic Loci and Candidate Genes Governing Root System Architecture in Soybeans

Root system architecture is important in soybean to improve water acquisition and nutrient efficiency under limited growing environments. Root traits are also most desirable to govern drought avoidance mechanisms under drought stress conditions. Limited effort has been made to improve the genetic potential of soybean root traits because of root phenotyping difficulties. Only a few root QTL mapping studies were reported to map root traits (manually measured/visually scored) with soybean intra specific population. But the genetic potential available within wild soybean, Glycine soja never been tapped to find novel loci to improve root system architecture in cultivated soybean. So we utilized intra specific mapping population developed to identify novel alleles from wild soybeans. We used different mapping populations developed using backcross (Dunbar/PI PI326582A) and single seed descent approach (V71-370/PI407162; Williams 82/PI 483460B) to generate root phenotypic data using Winrhizo software and to map seedling stage root QTLs. In these population candidate genes were mined in the QTL regions to understand the genetic components involved in designing root development and structure. The genetic variability among soybean germplasm (252 diverse soybean Plant Introductions) is also explored to identify candidate genes governing root system architecture, using genome wide association approach with 50K SNP data.