Evaluation of sesame (Sesamum indicum L) Genotypes to the shaded uplands of southern region

Abstract

The present investigation on ‘Evaluation of sesame (Sesamum indicum L.) genotypes to the shaded uplands of Southern region’, with an objective to identify sesame genotypes suitable for shaded uplands, was conducted at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2011-2013. The germplasm was evaluated for morphological traits and yield attributes, genetic variability, degree and direction of association, direct and indirect effects of various components on yield and genetic divergence analysis. The sesame germplasm consisting of thirty three accessions collected from different parts of Kerala, Karnataka and Maharashtra were assessed for the extent of variability, heritability and genetic advance, the relationship among the yield and associated traits, the direct and indirect effects of characters towards yield and divergence of different genotypes.Analysis of variance showed significant differences among the genotypes for almost all the characters studied. High and moderate phenotypic and genotypic coefficients of variation (PCV and GCV) were noticed for most of the yield contributing characters. Highest and lowest PCV and GCV were recorded for number of capsules per unit length and 1000-seed weight respectively. High estimates of heritability coupled with high to moderate genetic advance as per cent over mean was recorded for all the yield associated traits except for days to maturity, oil content and 1000-seed weight, which exhibited high heritability with low genetic advance indicating non-additive gene action. Yield had positive and significant association with the yield contributing characters such as plant height, number of primary branches, number of capsules per plant, length of capsule and number of seeds per capsule, signifying that selection based on these characters may improve yield. The highest genotypic and phenotypic correlation with yield was observed for number of capsules per plant. Path analysis revealed that number of capsules per plant had the highest positive direct effect on seed yield per plant followed by number of seeds per capsule. Number of primary branches per plant and days to maturity had the maximum positive indirect effect on seed yield per plant through number of capsules per plant. The thirty three genotypes were grouped into six clusters among which cluster IV, V and VI had only one genotype each. Maximum number of genotypes were grouped in cluster I with thirteen genotypes. The intercluster distance was maximum between clusters IV and VI whereas it was minimum between clusters V and VI. The selection indices were worked out for thirty three genotypes based on yield and yield attributing characters. Based on the ranks obtained, the genotypes SI 7 (RT - 351 from ORARS, Kayamkulam) and SI 12 (DS - 5 from Dharwad) were the superior genotypes identified which are suitable for the shaded uplands. These genotypes possessed maximum number of capsules per plant, length of capsule and number of seeds per capsule and seed yield.