Assessment of Phenotypic Divergence in a Collection of Sesame (Sesamum Indicum L.) Germplasm

Sesame (Sesamum indicum L., 2n = 26) is the fifth important oilseed crop of India after soybean, rapeseed - mustard, groundnut and sunflower. It is a short duration crop with high yield potential but generally low yields have been observed in the country. In this study, 146 sesame world germplasm accessions of Indian and exotic origin representing diverse growing regions and geographic origins were evaluated for phenotypic divergence on the basis of 13 agro-morphological traits and two biochemical traits. Among the evaluated traits viz., days to 50 per cent flowering, days to 100 per cent flowering, days to complete flowering, days to maturity, plant height, pods on main shoot, pod length, seeds per pod, seed size, seed yield per plant and per cent oil content revealed significant variation in the germplasm. The data of these traits were subjected to D² analysis which allowed grouping of accessions into 13 clusters indicating the presence of genetic diversity in the material. The distribution patterns of the accessions into different clusters indicated that clustering was not as per geographic origin. The inter-cluster distances were higher than the intra-cluster distances supporting the grouping of the accessions. Total number of pods per plant, plant height, main shoot length and seeds per pod had greater contribution towards the observed genetic divergence. Principal component analysis also supported the contribution of total number of pods per plant, main shoot length and plant height towards divergence on the basis of PC1, PC2 and PC3. Therefore these traits should be utilized as a parameter for selection of parents for obtaining good recombinants in sesame hybridization programme.