Genetic parameters, diversity and character association studies in germplasm lines of castor (Ricinus communis L.)

Castor is an important non-edible oilseed crop having huge industrial and export potential. It is used as an efficient lubricant for high-speed engines and as an ingredient in several commodities. There is a critical need to identify or to improve the germplasm lines with desirable characters. In the present study, 82 germplasm lines were evaluated in augmented design to estimate the genetic parameters viz., PCV, GCV, heritability and genetic advance as per cent of mean, principal component analysis and correlation studies. Results showed that the difference between PCV and GCV was low indicating less impact of environment on trait expression. Heritability (broad sense) and genetic advance as per cent of mean values were high for all the traits thus role of additive gene action is found important in governing the traits. Cluster analysis studies revealed that all the genotypes were grouped into eight clusters and cluster VIII documented the highest mean values for hundred seed weight and plant yield. The entries PRC-2 and PCS-337 recorded higher hundred seed weights of 56.5 and 48.6 g, respectively and in turn higher yield. These lines can be utilized as parents in the hybrid development programme for yield improvement. Correlation studies revealed that plant yield showed a significant positive association with all the characters except for days to 50% flowering. Thus selection for these traits viz., primary spike length, effective primary spike length, the number of effective spikes per plant, the number of capsules per spike and hundred seed weight will be advantageous in attaining higher yields.