Combining ability and heterosis for grain minerals, grain weight and yield in pearl millet and SSR markers based diversity of lines and testers

Abstract

Pearl millet, a versatile and historic coarse grain crop, is stable food for millions of people in India and sub-Saharan Africa. As part of a key initiative to increase its grain mineral content, an investigation was carried out with line × tester analysis to generate information on magnitude of heterobeltiosis and standard heterosis, gene effects, combining ability effect of parents and hybrids for grain yield, grain weight and grain minerals (iron, zinc, copper and manganese). The partitioning of variance due to parental genotypes revealed that lines and testers significantly differed for studied traits. The per se performance of hybrids was higher than parents in desired directions for most of the characters suggesting the possibility of heterotic hybrids. The potence ratio was less than 1 for all traits except Fe. The analysis of variance for combining ability revealed importance of both additive and non-additive components of genetic variance. On the basis of per se performance and combining ability analysis cross ICMA 98444 × AIB 220 may be directly exposed for commercial cultivation and may be advanced for development of parental genotypes. During SSR marker based study, maximum PIC value was revealed by Xpsmp 2203 (PIC value = 0.92). Clustering analysis could group parental genotypes in three main clusters. The genetic distance among 15 genotypes ranged from 0.29 to 0.83. The genetic relationships identified among the male sterile/restorer lines may be useful in designing strategies to improve the genetic variation in the context of pearl millet breeding and to develop heterotic crosses.