Assessment of genetic diversity in elite wheat genotypes using simple sequence repeat and quality protein markers

Abstract

In this investigation, Genetic diversity (GD) analysis of forty two elite Indian wheat genotypes representing different agro-climatic zones of India was determined using set of sixteen STS and 36 SSR markers. In total, 86 alleles were detected and polymorphism information content (PIC) ranged from 0.09 (Xwmc227) to 0.99 (Xgwm165) with a mean of 0.56, indicating sufficient discrimination by markers. Among the seven homologous chromosome groups, GD was highest in group 4 followed by lowest in group 3 and 6. The B- genome contained the highest mean number of alleles (2.6) followed by the A- and D- genomes (2.3 and 2.1, respectively). Cluster analysis based on SSRs and quality protein markers identified three distinct clusters. Principal component analysis (PCA) obtained from molecular data shows that the first two components justified 38.04% of total variance. Further, these elite lines were also characterized for HMW using SDS-PAGE. For the Glu-1 loci, 10 alleles were detected, 3 at the Glu-A1 locus, 5 at the Glu-B1 and 2 at the Glu-D1. The range of frequency in 10 HMW-GS combination was 3.2% to 74.2% in the advanced lines. At the Glu-D1 locus, the subunits 1Dx5+1Dy10 was present in 74.2% of the lines followed by the subunit 1Dx2+1Dy12 with a frequency of 25.8%. The subunit 1Dx5+1Dy10 was predominantly observed in these advanced lines having a stronger effect on bread making quality. This study provides evidence about genetic divergence and distinctness including quality traits in elite Indian wheat genotypes evaluated under the umbrella of All India coordinated wheat and barley improvement programme and serve as new source of genetic variation for wheat improvement.