Genetic analysis for yield and its components in sesame
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Date
2014
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JNKVV
Abstract
ABSTRACT
Sesame (Sesamum indicum L.), a crop from family Pedaliaceae is the most ancient oilseed crop. The present investigation entitled “Genetic Analysis for Yield and its Components in Sesame” was conducted under Project Coordinating Unit (Sesame and Niger) Research Farm, JNKVV, Jabalpur (M.P.) during kharif 2013. This investigation was carried out with sesame (96 +
1 check) germplasm in Randomized Complete Block Design in two replications. Observations were recorded on six randomly selected plants from each replication per treatment. Data were recorded on days to 50% flowering, days to maturity, plant height, number of capsules/plant, number of primary branches/plant, number of secondary branches/plant, capsule length, 1000 seed weight, oil content (%) and seed yield /plant. The objective of this study was to characterize sesame germplasm and estimate the genetic variability, heritability, genetic advance, association analysis, path coefficient analysis, genetic divergence and principal component analysis for yield and yield attributing traits.
Sesame germplasm lines were categorized in different groups on the basis of characters such as flower petal color, stem hairiness, leaf size, plant branching pattern, leaf lobes, locule number, leaf serration of margin, leaf axil, seed coat colour, capsule arrangement, capsule shape and flower petal hairiness.
Analysis of variance revealed sufficient and desirable amount of variability for most of the characters which indicates that there is enough scope for selection considering these characters.
The phenotypic coefficient of variation was significantly higher in magnitude than genotypic coefficient of variation for all the characters under study. Number of secondary branches/plant recorded the highest PCV and GCV followed by number of capsules/plant and number of primary branches/plant. Low PCV and GCV was recorded for days to maturity.
The highest heritability was exhibited by oil content, days to 50% flowering, number of capsules/plant, plant height and 1000 seed weight. Low heritability was recorded for number of secondary branches/plant, number of
primary branches/plant, seed yield /plant, capsule length and days to maturity. The highest genetic advance as percentage of mean (at 5% selection intensity) were recorded for number of secondary branches /plant and number of capsule /plant. High heritability coupled with high genetic advance was exhibited by number of capsules/plant hence, this trait is governed by additive genes indicating that direct selection would be effective for sesame improvement.
The results revealed that the estimates of genotypic correlation coefficients were higher than the phenotypic correlation coefficients. Seed yield/plant showed highly significant positive association with plant height, number of primary branches, number of capsules/plant, 1000 seed weight and oil content whereas, significant negative correlation was exhibited with capsule length.
Path coefficient analysis revealed that substantial positive direct effect on seed yield was exerted by oil content, plant height, number of primary branches/plant, number of capsules/plant, number of secondary branches/plant and 1000 seed weight, whereas, negative effect was exerted by days to 50% flowering, days to maturity and capsule length.
Based on the studies of correlation and path analysis, the characters number of primary branches/plant, number of capsules/plant, plant height, 1000 seed weight and oil content can be considered for formulating high yielding plant ideotype.
Tocher’s method resulted in formation of fifteen clusters. Clustering of germplasm was not associated with the geographical distribution and mainly grouped due to their morphological differences. The percentage contribution towards genetic divergence by oil content was maximum while, days to 50% flowering, number of capsules/plant showed moderate contribution to genetic divergence. The highest intra cluster distance was recorded in cluster V followed by cluster IV. The inter cluster distance was highest between the cluster VI and cluster XV followed by cluster VIII and cluster XV indicating that superior hybrids or recombinants can be realized by mating between the lines of the clusters i.e. S-0069, ES-334962 and GRT-83128 in a definite fashion.
The lowest inter cluster distance was observed between cluster III and cluster VI. Crossing between germplam belonging to the same cluster might not be expected to yield desirable segregates.
Principal components analysis was performed using phenological and yield components for sesame germplasm. Out of ten, only nine principal components (PCs) exhibited more than 0. 5 eigen value and showed about 95.19% total variability among the characters studied. PC1 showed 20.328% while, PC2, PC3, PC4, PC5, PC6, PC7, PC8 and PC9 exhibited 15.375%, 13.281%, 10.508%, 8.968%, 8.483%, 6.823%,
6.051% and 5.381% variability, respectively among the germplasm for the traits under study. Rotated component matrix revealed that the PC1 accounted for the most physiological and yield contributing traits like plant height, number of capsules/plant, number of primary branches/plant, 1000 seed weight and seed yield/ plant. PC2 was also dominated by yield related traits i.e. number of secondary branches/plant, capsule length and 1000 seed weight. The PC3 was dominated by yield and quality related traits i.e. oil content (%), and days to maturity. W hile, PC4 was more related to physiological traits like days to 50% flowering.
An intensive selection procedures can be designed to bring about rapid improvement of dependent traits i.e. yield and oil content in sesame by selecting lines ES-334962, EC-334992-1, NIC-7982, IS-424, S-
0627, S-0069, ES-173, G-19 and GRT-8392 from PC1and PC3 which can be used for further breeding programmes.