Investigation of genetic variability in castor (Ricinus communis L.) accessions through principal component analysis

Abstract

In this study 100 castor germplasmaccessions along with 4 checks(DCS-9, DCS-107, DCH-177 and DCH-519)were examined for genetic variability and agro-morphological traits at All India Co-ordinated Research Project on Castor, Zonal Agricultural Research Station, GKVK, Bengaluru during kharif 2019. The analysis of variancerevealed that, castor accessions differed significantly for all the targeted traits except number of effective spikes per plant, which indicates considerable variability exists among the germplasm accession studied. The outcome of Principal Component Analysis (PCA) indicated that,four principal components (PCs) having eigen values more than one with 79.36% of the total variation among the 104 genotypes. Further, the PC 1 accounts 38.94% variation followed by PC 2 with17.88%, PC 3 with 13.98% and PC 4 with 8.55% variation. The germplasm studied were grouped into eleven main clusters. Cluster-I consist of 29 genotypes which was found to be a largest cluster, whereas, cluster VIII, IX, X and XI consists of single genotype in each cluster and they had solitary entries viz., HCG-21, HCG-116, BCG-23 and HCG-80 respectively. Based on values of inter cluster distance, it was found that the highest divergence occurred between cluster X and XI (18772790.00). The cluster X involved BCG-23 which is high yielding (223.40g/plant), bold seeded (40.99g/100 seed weight) and better than checks and cluster XI had HCG-80, these could be utilized in heterosis breeding to get superior recombinants.