Uncovering of natural allelic variants of key yield contributing genes by targeted resequencing in rice (Oryza sativa L.)

Abstract

In rice (Oryza sativa L.), during the course of domestication, numerous beneficial alleles remain untapped in the progenitor wild species and landraces. This study aims at uncovering these promising alleles of six key genes influencing the yield, such as DEP1, Ghd7, Gn1a, GS3, qSW5 and sd1 by targeted resequencing of the 200 rice genotypes. In all, 543 nucleotide variations including single nucleotide polymorphisms and insertion and deletion polymorphisms were identified from the targeted genes. Of them, 225 were novel alleles, which identified in the present study only and 91 were beneficial alleles that showed significant association with the yield traits. Besides, we uncovered 128 population-specific alleles with indica being the highest of 79 alleles. The neutrality tests revealed that pleiotropic gene, Ghd7 and major grain size contributing gene, GS3 showed positive and balanced selection, respectively during the domestication. Further, the haplotype analysis revealed that some of the rice genotypes found to have rare haplotypes, especially the high yielding variety, BPT1768 has showed maximum of three genes such as Gn1a-8, qSW5-12 and GS3-29. The rice varieties with novel and beneficial alleles along with the rare haplotypes identified in the present study could be of immense value for yield improvement in the rice breeding programs.