Insight into the genomic diversity: Genome wide association study unveils the SNP diversity in horsgram germplsam

Abstract

Genome wide association study (GWAS) was performed to identify loci associated with three agronomic traits namely seeds per pod, pods per plant and number of seeds per plant of horsegram (Macrotyloma uniflorum). Total 87 accesions of horsegram from different geographical regions of India and one wild relative from Australia were utilised for the genome wide association studies. The genotyping was carried out using genotype-by-sequencing technology and after high quality filtering, minor allele frequency of 0.05, a total of 55,656 quality SNPs were utilised for determining Marker-Trait Association. The LD decay varied across the chromosomes form 8 kb to 300 kb. Further, the population structure analysis has clustered the accession into three subpopulations. All the 88 accessions of horsegram were evaluated at Palampur (32.1109° N, 76.5363° E) and Bajaura (31.8465°N, 77.1605°E) locations of North-Western Himalayan region, India from. In the current study, 143 MTAs associations were observed for seeds per pod distributed on all 8 chromosomes, 2 for pods per plant at chromosomes 2 and 3 and 1 for number of seeds per plant at chromosome 7. However, total 11 stable QTLs (9 for number of seeds per plant and 2 for pods per plant) were also identified. These QTLs can serve as a potential source for marker assisted selection. The genes identified within and in proximity to the stable QTLs will serve as a bridge between genetic information and its practical application for crop improvement.