A unique hybrid parental line identification system using obcordate leaf shape marker in Pigeonpea

Abstract

Pigeonpea has been ushered in to the group of cultivated crops where heterosis has been commercially exploited through hybrid development. The male sterile parental lines derived through CGMS technology transmuted the crop from often cross pollinated nature to completely cross pollinated. Maintenance of purity by following principles of seed production is a prerequisite in commercial hybrid seed production. To enhance efficacy of hybrid seed production and for easy identification of off types in the parental lines obcordate trait (single gene recessive) has been introgressed in male sterile line. The hybrids derived from crosses involving obcordate leaf A-lines and normal leaf fertility restorers (R-lines) were fully fertile and had normal lanceolate leaves; thus the difference between A-line and hybrids was clear. The use of obcordate leaf as a NEP (naked eye polymorphic) marker in pigeonpea would contribute to preserve parental line purity and confirm hybrid status. Heterotic hybrid combinations are developed by using the female parent with this NEP trait exhibited 30 to 40 per cent superiority in yield over high yielding ruling varieties. Among male sterile (A) lines, ICPA 2204 and ICPA 2203 were the best general combiners and among testers, ICPL 20116 and ICPL 20108 were the best general combiners. Obcordate female parent based hybrids ICPH 4563, ICPH 4567 and ICPH 4564, were the best with positive significant SCA effect and higher mean performance for grain yield, 100-seed mass, number of seeds/pod and resistance to wilt disease