HETEROSIS AND COMBINING ABILITY FOR YIELD AND YIELD COMPONENT CHARACTERS OF NEWLY DEVELOPED CASTOR (RICINUS COMMUNIS L.) HYBRID

Abstract

The estimates of the components of genetic variation were worked out by Kempthorne method from a Line x Tester analysis in castor for fourteen plant type related traits. The analysis for combining ability revealed significant mean sum of squares of both general combining ability (GCA) and specific combining ability (SCA) for all the characters which indicated the presence of both additive and non-additive gene actions. The ratio of GCA variance and SCA variance ratio revealed the predominance of non-additive gene action for all the traits except plant height up to primary spike, no. of nodes up to primary spike, no. of capsules/primary spike and total spike length of secondary. JP-87 was good general combiner for most of the characters including seed yield. The line DCS-106 was also a good general combiner for early flowering, days to maturity and number of capsules on secondary spike. Cross JP-87 × RG-1740/A was a good specific combiner for seed yield per plant and for other yield component. The hybrid DPC-9 × RG-156 with good specific combining ability for days to maturity can be used for yield improvement in castor. In general for yield and other yield attributing traits the promising hybrids with high heterosis were JP-87 × RG-1740/A, JP-87 × DCS-106, DPC-17 × RG-156, DPC-17 × DCS-106 and DPC-17 × DCS-107 were on par with the check. These cross combinations could be utilized for further use in breeding programme for improvement in yield of castor.