Studies on inheritance of male-sterility in Cajanus cajan × C. acutifolius crosses

Among foodlegumes, the first evercommercial hybrid breeding technology was developed in pigeonpea (Cajanus cajan (L.) Millsp.). For a long-term sustainability of hybrids both genetic as well as cytoplasmic diversityof thehybrid parents is essential. At present A2 and A4 CMS systems are being used in hybrid pigeonpea breeding. In this paper a case of maternal inheritance of male-sterility conditioned by the cytoplasm of cultivated pigeonpea is reported. This study was made in crosses involving cultivated genotypes as female parents and a wild relative of pigeonpea, Cajanus acutifolius, as male parent. The segregation data in F1, BC1F1, and BC2F1 generations established maternal inheritance of male-sterility. This source of CMS, when stabilized through backcrossing and selection to a productive recurrent parent,will provide much needed additional cytoplasmic diversity for the future hybrid breeding programs.