studies on genetic diversity heterosis and combining ability of pistillate and monoecious lines in castor ricinus communis

Abstract

In the present investigation, 68 castor genotypes were raised in Randomized Block Design newlinewith two replications at Tapioca and Castor Research Station at Yethapur, during Rabi 2015-16, to newlinestudy the extent of genetic variation, character association, direct and indirect effects and genetic newlinediversty. Observations were made for eleven quantitative characters viz., days to 50 per cent newlineflowering, days to 50 per cent maturity, plant height, number of nodes up to primary spike, length newlineof primary spike, effective length of primary spike, number of capsules on primary spike, total newlinenumber of spikes, 100 seed weight, oil content and seed yield per plant. newlineThe observations on these characters were subjected to Analysis of variance. The analysis of newlinevariance showed significant differences among all the estimates studied. High degree of phenotypic newlineand genotypic coefficient of variations were observed for seed yield per plant, number of capsules newlineon primary spike and total number of spikes per plant. High heritability coupled with GAM was newlineobserved for seed yield per plant, plant height, total number of spikes per plant, number of capsules newlineon primary spike, 100 seed weight, effective length of primary spike and length of primary spike newlinecharacters. This number of nodes up to primary spike character indicates presence of additive gene newlineaction in inheritance of these characters which can be further improved by following simple newlineselection. newlineCorrelation between yield and other ten quantitative characters were studied. Seed yield per newlineplant exhibited significantly positive correlation with number of capsules per primary spike and newlinetotal number of spikes. In the path analysis, seed yield per plant was directly and positively newlineinfluence by effective length of primary spike, total number of spikes, number of capsules on newlineprimary spike and plant height. Hence direct selection for yield through these traits would be newlineeffective. newlineBased on the D2 analysis data, 68 castor genotypes were grouped into fourteen clusters using newlineTocher s method. Cluster I was