Qualitative trait loci analysis for seed yield and component traits in sunflower

Abstract

The present investigation was carried out to identify the molecular markers associated with various characters in sunflower using recombinant inbred lines. Linkage analysis was carried out and five linkage groups were  obtained with 19 simple sequence repeats (SSR) markers. Linkage map
construction, single marker analysis (SMA) and composite interval mapping analysis were carried out with SSR primers and quantitative traits. In SMA, out of 50 SSR markers, a total of 29 SSR markers were found to be significantly linked to various traits. The adjusted R2 for the regression equation varies from 3.2 to 29.8%. Two traits namely, days to flowering and seed color recorded above 20% R2 value. Hull weight recorded above 10% R2 value. In inclusive composite interval mapping (ICIM), the quantitative trait loci (QTL) analysis resulted into two QTLs namely, seed and volume weight. QTL analyses were performed through inclusive  composite interval mapping (ICIM). The QTL analysis revealed each one
QTL for traits namely, stripes on seed margin, stripes between seed  margin, 100-seed weight and seed yield. The LOD ranged from 1.5 to 1.9. The adjusted R2 value ranged 10.6 (seed yield) to 65.0 (stripes between seed margin) percent. Among these QTL, QTL on stripes on seed margin and stripes between seed margin may be considered as potential as they recorded very high phenotypic variation accounted. As the distance between the flanking marker is more than 5 cm, fine mapping of this QTL region with more markers may be attempted to utilize these QTL in the marker assisted back cross programme.

Key words: Sunflower, Simple sequence repeats (SSR), quantitative trait loci (QTL), hundred seed weight, stripes on seed margin, stripes between seed margin, seed yield.