Application of heterotic grouping, standard heterosis and performance in breeding high-yielding inbred and hybrid cultivars of pigeonpea

Abstract

A set of 102 hybrid combinations, developed by crossing three A4 CMS lines and 34 diverse testers, was evaluated to identify potential parental genotypes for breeding new high yielding cultivars. The hybrid combinations were assessed for their performance, standard heterosis and combining ability. Significant differences were recorded for parents versus hybrids for yield and its related traits, suggesting the presence of substantial heterotic responses. Highly significant GCA effects for yield were recorded within the female parents and testers. Relatively more number of hybrids involving ICPA 2092, as female parent, exhibited significant positive SCA values for yield, days to flower, plant height, primary branches, pods/plant, seed size and seeds/pod. A total of 45 hybrids recorded significant SCA effects for productivity. The yield superiority of hybrids over the inbred control cultivar ranged from 50.81 to 76.89%. Interestingly, 23 hybrids were also found superior to the first released pigeonpea hybrid ICPH 2671 by a margin of 5.48% to 64.31%. On the basis of their performance in hybrid combinations, the testers were classified into seven heterotic groups. The present study identified two CMS lines (ICPA 2092 and ICP 2043) and 13 testers including ICP 3525, ICPL 20196, BDN 2001-6 and BSMR 198 etc. as potential parental lines for use in breeding medium duration pigeonpea pure line and hybrid cultivars.