Development Of Introgression Lines And Validation Of Quantitative Trait Loci (Qtl) Conferring Transgressive Variation For Yield In Rice

Abstract

A set of introgression lines (ILs) were developed in an advanced backcross population from a cross between the donor, O. rufipogon (IRGC 105491) in the genetic background of an elite U.S. variety, cv Jefferson, to confirm the performance of six yield-enhancing QTLs identified from a previous study. At the BC3F4 generation, 50 lines containing the donor alleles at the target QTL regions and the least number of background introgressions were selected for evaluation in standard yield plots at four locations in southern U.S. rice growing regions. The top performing lines were genotyped with fixed SNP assays to provide a higher resolution definition of the size and location of donor introgressions in each IL. Based only on genotypic data, 1-2 plants/family were simultaneously selected for an additional backcrossing to Jefferson and screened with SSRs and InDel markers for selecting individuals with minimum background, and for recombination within the target QTL regions as the basis for fine mapping. NIL status was confirmed using the 384 SNP assay and additional genotyping conducted with SNP markers.