Heterotic and Combining Ability Estimates Using Seed Yield and its Components for Assessing Potential Crosses to Develop Ft Hybrids in Castor Over Ennvironment

摘要

Heterosis and combining ability estimates are very useful genetic parameters for identification of potential crosses to develop castor hybrid. The crosses were attempted in a line X tester mating design, which involved four female and ten tester parents, thus 40 F hybrids were developed. The experiment was carried out in a randomized complete block design with three replications. The mean squares due to general combining ability (GCA) of lines and testers and specific combining ability (SCA)of lines x tester interactions were significant. The significance of GCA and SCA variances suggested non-additive gene action for controlling all the characters. The high but parallel expression of SCA and heterosis determines the involvement of dominant genes and suitability of Ft crosses for development of hybrid in castor. Two F, hybrid; JP-65 x JI-398 and SKP-84 x ANDCI-10-4 manifested higher magnitude of SCA effects for seed yield, length of primary raceme, number of effective branches perplant, number of capsules on primary raceme and 100 seed weight. Almost this two F, hybrids also demonstrated higher heterobeltiotic effects for above same traits. The positive association between SCA and heterobeltiotic effects further determined the reliability of these two genetic parameters to identify potential F, hybrids.