Genetics of Fertility Restoration in A4-Based, Diverse Maturing Hybrids of Pigeonpea (Cajanus cajan (L.) Millsp.)

Abstract

Recently, a breeding technology for hybrid pigeonpea (Cajanus cajan (L.) Millsp.) based on cytoplasmic-nuclear male sterility (CMS) and partial natural outcrossing was developed at ICRISAT. The limited number of experimental hybrids tested has shown the presence of a considerable amount of hybrid vigor for seed yield. In the present study, one extra-early- (120 d), two early- (150 d), and two late-maturing (180 d) pigeonpea hybrids were studied to generate information on the genetics of fertility restoration of the A4 CMS system. In the extra-earlymaturing hybrids, pollen fertility was controlled by a single dominant gene, whereas in the earlyand late- maturing hybrids, male fertility was governed by two duplicate dominant genes. It was also observed that hybrids with two dominant genes produced a greater pollen load and expressed greater stability as compared with those carrying a single dominant gene. The information on the inheritance of fertility restoration will help in designing strategies for breeding elite hybrid parents, and it was concluded that for breeding hybrids with stable fertility restoration, the presence of two dominant genes is essential