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Genetic studies in Sesamum (Sesamum indicum L.)

KrishiKosh

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Title Genetic studies in Sesamum (Sesamum indicum L.)
 
Creator Chaudhari, G.B.
 
Contributor Naik, M.R.
 
Subject planting, yields, environment, heterosis, sowing, crossing over, developmental stages, genotypes, biological phenomena, oilseeds
 
Description An experimental material comprising of five lines, ten testers and their fifty crosses developed through line x tester mating design along with two standard checks viz., Gujarat Til-4 and TKG-22 were grown in a randomized block design, with three replications, in three diverse environments during 2012-13. Three environmental situations were different locations viz., Navsari, Acchaliya and Vyara.
The objective of the study was to identify prospective, stable and heterotic crosses of sesamum suitable for cultivation over a wide range of locations. Therefore, the magnitude of heterosis over better parent and standard checks viz., Gujarat Til-4 (Local check) and TKG-22 (National check), combining ability of parents and nature of gene actions for various quantitative traits as well as genotype x environment interactions and stability parameters were studied. The observations were recorded for seed yield and its attributes along with quality parameters such as oil and protein content.
The analysis of variance revealed significant differences among genotypes for all the characters studied. The significant mean squares due to genotype x environment interaction for grain yield and yield contributing traits emphasized that genotypes reacted differentially to the environments. Perusal of mean performance of parents over environments revealed that parents : JLS-110-12, JLS-9707-2,
AKT-64, JLT-7 and Phule Til No.1 were superior in respect of seed yield per plant, whereas among crosses, G.Til-3 x AKT-64, G.Til-3 x PKV-NT-11 and G.Til-3 x AKT-101 were found superior.
The magnitude of heterosis over environments revealed that crosses: G.Til-3 x PKV-NT-11, G.Til-3 x AKT-101 and G.Til-3 x JLT-408 manifested high heterobeltiosis and standard heterosis over both the standard checks i.e., G.Til-4 and TKG-22. Crosses showing high heterobeltiosis and standard heterosis over both the checks for grain yield per plant, in general also manifested desirable
heterotic effects for two or more important yield contributing characters.
Combining ability analysis over environments revealed importance of both additive and on-additive components. Perusal of σ 2 gca/ σ 2 sca ratio revealed preponderance of additive gene action for seed yield per plant, capsules per plant, capsule length, 1000-seed weight, oil content and protein content. While, the characters, days to 50% flowering, days to maturity, plant height, branches per plant and seeds per capsule were controlled by non-additive gene action, suggesting in general, the importance of both additive and non-additive gene actions for inheritance of component traits. As preponderance of additive gene action and high heterosis is conspicuous for seed yield and majority of yield contributing characters in the present investigation, it is recommended that heterosis breeding can be used for exploitation of hybrid vigor.
The parents, G.Til-3 and JLS-116 besides being best general combiners among females and males, respectively for seed yield per plant were also found to be good combiners for majority of the yield components suggesting that these parents possessed good source of favorable genes for increasing overall production in sesamum.
The per se performances of parents and crosses were related to gca effects of parents and sca effect of crosses, respectively for majority of the characters. Consequently, the scope of a genotype to be used as a parent in hybridization programme or a cross to be used as a commercial hybrid might be judged by comparing per se performance of parents and crosses along with gca of parents and heterotic response of crosses, respectively. The crosses exhibiting high per se
performance, high heterosis and significant desirable sca effects for various traits involved either good x good, good x poor, good x average or poor x good combining parents. The crosses exhibiting high sca effects did not always involve the parents with high gca effects, thereby suggesting the importance of inter-allelic interaction. However, it was observed that at least one good general combining
parent was involved in desirable specific combination.
The analysis of variance for phenotypic stability indicated that the variation due to genotype x environment interaction was considerable for all the characters except for protein content. The significance of G x E (linear) and pooled deviation for majority of the traits suggested the importance of both linear and non-linear components in determining total genotype x environment interactions.
Perusal of stability parameters revealed five parents and one check (G. Til-4) exhibiting higher mean seed yield, unit regression (bi) and least deviation from regression (S 2 di) and therefore they were classified as stable with average response to environments.
Among the crosses three crosses were found stable with average response to environments and five crosses registered specific adaptability for favorable environments, while the combination G.Til-3 x JLS-110-12 showed specific adaptability to poor environments for seed yield per plant.
The best crosses viz., G.Til-3 x AKT-101 , Patan-64 x JLS-110-12 and G.Til-1 x JLT-7 were found to have average stability over environments for seed yield per plant with one or more stable yield contributing traits. These crosses also manifested high per se performance, significant eterobeltiosis and standard heterosis over both the standard checks (G.Til-4 and TKG-22) with either significant positive or positive sca effects for seed yield and some of its important components, signifying their potential for commercial exploitation for genetic improvement in sesamum
 
Date 2016-05-03T10:43:23Z
2016-05-03T10:43:23Z
2014
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/65738
 
Language en
 
Format application/pdf
 
Publisher NAU