Combining ability studies of pigeonpea cytoplasmic male sterile (CMS) lines with an obcordate leaf marker

Hybrid pigeonpea [Cajanus cajan (L.) Millsp.] breeding technology based on cytoplasmic male sterile (CMS) was recently developed in India. A program was initiated to track the purity of female parental lines by incorporating an obcordate leaf shape marker in established male sterile A-lines. Seven obcordate A-lines developed by backcrossing and selection were crossed with four known fertility restorers in line x tester mating design to study their general and specific combining ability. Higher magnitude of specific combining ability (SCA) effect showed that, hybrid yield was under the control of non-additive genes. Among A-lines, ICPA 2204 was the best general combiner. Among testers, ICPL 20116 was the best general combiner. Among hybrids, ICPA 2208 x ICPL 20108 a cross between high general combining ability (GCA) parents was the best with positive significant SCA effect and higher mean performance for grain yield, 100-seed mass, number of seeds/pod and resistance to fusarium wilt disease. The success of this technology will help to address the issue of seed purity to some extent.