Development of CGMS Systems in Pigeonpea with Special Reference to A2 Source of Cytoplasm

Background: Exploitation of hybrid vigour is quite possible in cross-pollinated crops. However, pigeonpea is a grain legume crop with a moderate level of cross-pollination (20-70%), with diploid (2n = 2×) chromosome number of 22 and genome size of 1C = 858 Mbp. Outcrossing mainly aided by insect pollinators. Commercialization of CMS based hybrid is constrained because of the labor intensiveness of seed production and concerns about seed purity. In pigeonpea, two dominant genes (Rf1 and Rf2) have been identified and reported by Saxena et al., (2011), which impart fertility restoration to the hybrid plants. The fertility restorer (Rf or Fr) genes in the nucleus suppress the male-sterile phenotype and allow the production of high yielding CGMS-based hybrids. Cytoplasmic male-sterile would effectively circumvent these constraints and revolutionize the hybrid seed industry. CGMS based hybrid breeding can be found more reliable to give productive hybrids in pigeonpea but need some expansion. Methods: In the present study, the objective was to develop cytoplasmic-genetic male-sterile (CGMS) lines in pigeonpea through wide hybridization involving conventional backcrossing. Five CGMS lines viz. BDN 2004-1A, BDN 2004-2A, BDN 2004-3A, BDN 2004-4A and BSMR 736A were developed from Cajanus scarabaeoides cytoplasmic background. This paper discusses development of A and B lines by using A2 CMS systems available for pigeonpea. Result: Our investigations on Development of CGMS systems in Pigeonpea with special reference to A2 source of cytoplasm have allowed us to diverse the male sterile lines based on Cajanus scarabaeoides (A2) cytoplasm in pigeonpea which can be used as marker for easy identification, however characterization of these mentioned five CGMS lines will also help in the predicting the performance of progenies in the different breeding programmes.