Genetic and molecular studies of chickpea genotypes for yield and its components
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Date
2016
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JNKVV
Abstract
ABSTRACT
The present investigation entitled “Genetic and Molecular Studies of Chickpea Genotypes for Yield and its Components” was conducted at seed breeding farm, Department of Plant Breeding and Genetics, College of Agriculture, J.N.K.V.V., Jabalpur, during Rabi 2015--16. Experimental material consisted of 50 genotypes (including 40 genotypes from BARC and 10 promising lines released from JNKVV, Jabalpur) grown in randomized complete block design with two replications.
The objective of this study was to systematically characterize and categorize chickpea genotypes based on qualitative characters, so that they could be easily distinguishable and distinct from one another for feasibility in identification at various levels and to study genetic variability, correlation coefficients, path coefficients and genetic divergence for yield and yield attributing traits and diversity analysis using SSR markers.
For characterization of genotypes, data were recorded on visual observation. Characterization of genotypes concluded that all the traits under study had sufficient amount of variability indicating that majority of genotypes have undergone changes during the evolution of this crop but there are still some genotypes which posse’s primitive characters.
Quantitative observations were recorded on 11 different yield and yield attributing traits. Analysis of variance indicated that the differences among genotypes were highly significant for all the traits studied and this indicated that the genotypes had sufficient amount of variability. Further, high genotypic and phenotypic coefficient of variation were found for seed yield per plant, 100 seed weight, biological yield per plant, number of effective pods per plant, number of seeds per plant and harvest index. High value of genotypic coefficient of variation indicates that presence of substantial amount of genetic variability in the population and there is little influence of the environment on the expression of the character. Moderate values were recorded for the characters viz, days to flower initiation, days to pod initiation and plant height whereas, low values of GCV and PCV was observed for days to maturity and number of seeds per pod.
Heritability and genetic advance are important selection parameters. In present study high heritability accompanied with high genetic advance was observed for effective number of pods per plant, number of seeds per plant and biological yield per plant indicating predominantly the presence of additive gene action in the expression of these traits and consequently chances of improvement of these traits through simple selection. High heritability with moderate genetic advance was recorded for days to flower initiation, days to pod initiation, seed yield per plant, harvest index, plant height, days to maturity and 100 seed weight.
Correlation analysis provides knowledge on the interrelationship of different independent traits with the dependent traits like seed yield per plant. In the present investigation genotypic correlation coefficients were higher in magnitude than the phenotypic correlation coefficients in the same direction and magnitude, indicating that there is strong inherent association between each pair of characters(s) which might be due to masking or modifying effect of the environment. Seed yield per plant shared strong significant and positive association with days to flower initiation, days to pod initiation, plant height, biological yield per plant, harvest index, number of effective pods per plant, total number of seeds per plant and 100 seed weight while significant and negative association of seed yield per plant was recorded with number of seeds per pod.
In order to find out the cause and effect relationship of seed yield per plant and its related characters, the path analysis was taken up in the present investigation and the results revealed that the highest positive direct effect on seed yield per plant was observed for biological yield per plant followed by number of seeds per plant, number of seeds per pod, days to maturity, plant height. It indicates true relationship between these traits and direct selection for these traits will be rewarding for yield improvement. Whereas, highest negative direct effect on seed yield per plant was observed for effective number of pods per plant followed by harvest index, 100 seed weight, days to flower initiation, days to pod initiation. It indicates that the restricted selection mode should be used for nullification of undesirable effects of these traits.
The divergence analysis revealed that the 50 genotypes were grouped into 10 clusters out of which four were multi genotypic and six were mono genotypic clusters. Cluster I was the largest among all the clusters consisting of 36 genotypes. Cluster III showed maximum intra cluster D2 value while, the highest inter cluster divergence was observed between genotypes of cluster IV and X. This showed wide diversity between them and the genotypes from these clusters can be used as parents in hybridization programme since this would produce wide variability and transgressive segregations with high heterotic effects.
Eleven SSR molecular markers, reported to be linked with different traits were used to assess the genetic diversity. Out of eleven markers, nine were reported to be polymorphic. The total number of alleles amplified was 26 with a mean value of 2.36. The highest number of alleles (4) was amplified by the marker TA78. Single unique allele was amplified by two markers viz., H1B17 and TA78. The major allele frequency ranged from 0.357 to 1.000. The cluster analysis on the basis of molecular study revealed that the selected 14 genotypes were divided into two major clusters. Further, Cluster I was divided into two sub- clusters. These sub-clusters further divided into several minor clusters. This depicted that there is considerable genetic variability amongst the genotypes used. The results of molecular study were found to be similar to the results of D2 analysis done on the basis of morphological data.
On the basis of selection criteria it is indicated that the genotypes viz., JG14, BARC 359, BARC 214, BARC 55, BARC 49, BARC 345, BARC39, BARC358, BARC360, BARC344, BARC378 and BARC 367 are superior in yield and yield attributing traits. Thus these genotypes might be tested in multilocational trials, to release as high yielding varieties of chickpea. Besides this, these genotypes may be used as parents in hybridization programme to improve the yield and its components.
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