Evaluation Of High Oil x High Oil Reciprocal Soybean Populations For Seed Oil QTL Identification.

Oil and protein composition of soybean [Glycine max (L.) Merr] seeds make soybean the second most valuable crop in the USA. Oil and protein composition has been studied extensively, and over 60 QTL have been identified for both traits. Oil biosynthesis and storage in developing soybean seeds involves a number of complex pathways and includes chloroplasts and mitochondria, which are maternally inherited in soybean. Each step in the oil biosynthesis and storage pathways involves at least one gene, which represents a potential QTL. In addition, environmental effects can affect oil and protein development in oilseeds. The objective of this study is to identify QTL associated with seed oil content in reciprocal bi-parental populations involving parents with moderate and high oil content. Reciprocal RIL populations containing 270 to 450 lines for each reciprocal cross were developed and evaluated for seed oil and protein content in three environments. Reciprocal populations should allow detection and dissection of putative cytoplasmic effects. Each population was grown in an augmented block design with block size of 18 with both parents included as common entries in each block. The populations were evaluated in two Nebraska environments and one tropical environment in Puerto Rico. Seed protein and oil composition BLUPs and LSMeans were obtained using the Proc Mixed and GLM procedures in SAS. Genotype analysis of the RILs was based on 15% tails of the phenotypic distribution in each population. Genotype information was based on the 1536 SNP Illumina^® GoldenGate Genotyping Assay. Results for the QTL analyses, genotype-environment interaction effects, and reciprocal cross effects will be presented and discussed.