Genetic mapping and validation of SSR markers linked to leaflet shape in soybean using a recombinant inbred line population

Abstract

The leaflet shape in soybean is an important trait and is genetically controlled by a single Ln locus. The narrow leaflet shape is associated with high photosynthetic efficiency and a higher number of seeds per pod. The current study involves the genetic mapping of SSR markers linked to leaflet shape in a F2:8 soybean recombinant inbred population and validation in different genetic backgrounds. A total of 240 SSR markers were used for bulked segregant analysis and six SSR markers (Sat_105, BARCSOYSSR_20_0813, BARCSOYSSR_20_0839, BARCSOYSSR_20_0846, BARCSOYSSR_20_0850, and BARCSOYSSR_20_0855) located on chromosome 20 were found to be linked to leaflet shape locus. The linkage analysis distributed these six SSR markers and leaflet shape (Ln) locus in one linkage group within a map distance of 11.5 cM. BARCSOYSSR_20_0839 and BARCSOYSSR_20_0846 were the two most tightly linked SSR markers and flanked the Ln locus at a distance of 0.3 cM and 1.8 cM, respectively. The markers selection efficiency varied from 86.6 to 99.4 per cent. The specificity of tightly linked SSR markers for leaflet shape was confirmed by validation on 24 different soybean genotypes. The SSR markers successfully distinguished the narrow leaflet genotypes from broad leaflet genotypes, indicating their specificity to leaflet shape locus and thus offer scope for further exploitation. Key words: Soybean, leaflet shape, SSR markers, Ln, genetic mapping, validation