Heterosis and combining ability studies for yield and its component traits in Lentil (Lens culinaris Medikus
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Date
2023-04
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G. B. Pant University of Agriculture & Technology, Pantnagar-263145
Abstract
The present investigation was undertaken at Pulse Breeding Block of N. E. Borlaug Crop Research Centre, GBPUA&T, Pantnagar, Uttarakhand, India, during rabi 2021-22 and 2022-23 crop seasons to estimate combining ability, gene action and heterosis; genetic parameters and genetic diversity in lentil.
A half diallel involving eight parents were used to produce 28 F1’s during rabi 2021-22. All the 37 genotypes including 8 parents, 28 F1’s and one check variety, PL 9 were evaluated in a Randomized Complete Block design (RBD) with three replications during rabi crop season of 2022-23. The observation on 8 different morphological characters were recorded and the appropriate statistical methods were used to draw the conclusion. ANOVA for diallel analysis resulted in significant mean sum of square due to parents and hybrids revealing the presence of considerable variability among them. The estimates of σ² SCA were found to be higher than the σ2 GCA for the traits days to 50% flowering, days to maturity, plant height and number of primary branches per plant, while for rest of the characters σ2 GCA were higher as compared to σ² SCA estimates. Higher SCA than the corresponding GCA indicates the presence of dominance gene action or non-additive gene effects as SCA is a function of dominance effect whereas, high GCA indicating the preponderance of additive gene action. The parent DPL 62 was found to be a good general combiner for five traits viz., days to 50% flowering, days to maturity, plant height (cm), 100-seed weight (g) and seed yield per plant (g). The hybrids PL 4 x PL 8 and PL 8 x L 4147 had good SCA effects for maximum seven characters viz., days to 50% flowering, days to maturity, plant height, number of primary branches, number of pods per plant, 100- seed weight and seed yield per plant. The standard heterosis for seed yield per plant over the check PL 9 ranged from -46.85% (PL 4 x L 4076) to 30.45% (PL 8 x DPL 62). Among the 28 hybrids, only five hybrids revealed significant and positive standard heterosis over the check variety PL 9 i.e., PL 8 x DPL 62, PL 8 x L4147, PL 8 x DPL 15, PL 8 x LH 84-8 and PL 8 x L 4076.
Genetic variability, inter-character association, path coefficient analysis and genetic divergence were studied in 25 lentil genotypes during rabi 2022-23. High PCV and GCV estimates were recorded for characters viz., seed yield per plant, primary branches/ plant, 100 seed weight, seeds per pod and pods per plant. High estimates of heritability coupled with high genetic advance as per cent of mean were observed for the traits plant height, primary branches per plant, pods per plant, seeds per pod, 100-seed weight and seed yield per plant which may be attributed to the preponderance of additive gene action and possess high selective value and thus, selection pressure could profitably be applied on these characters for their rationale improvement.The traits plant height and number of pods per plant had positive significant association with seed yield per plant at both genotypic and phenotypic level.These traits can be enhanced by selection, which will ultimately improve the economic yield per plant. Path coefficient analysis suggested that the trait pods per plant had high direct effect and positively correlated with seed yield.
Mahalanobis D2 statics, grouped 25 genotypes of lentil into five different clusters. The cluster I is largest containing 12 genotypes followed by cluster II with 10 genotypes and cluster III, IV and V with a single genotype each. Maximum inter-cluster distance was recorded between Cluster I and V (36.108) indicating that genotypes from these clusters were highly divergent meriting their consideration in selection of parents for hybridization. Based on the cluster means genotypes present in cluster II (PL-07, PL234, LL931, LL875, PL-05, K75, PL639, PL12, PL11 and KLS218) showed that the genotype in these cluster can be selected as early maturity in lentil breeding programme.
Molecular diversity among 25 elite lentil genotypes was carried out using 20 SSR markers. Out of 20 markers, five markers were found to be polymorphic. SSR 156 was found to be most informative marker as it recorded maximum PIC value of 0.696 and can be utilized for diversity analysis in lentil. The analysis of dendrogram revealing the relationship among 25 lentil genotypes. Jaccard similarity coefficient ranged from 0.45 to 0.94 among 25 genotypes. Clustering patterns obtained from the dendrogram clearly resolved the 25 genotypes into four distinct clusters. Cluster III was the largest cluster having 13 genotypes, followed by Cluster IV (7 genotypes), Cluster I (3 genotypes) and Cluster II (2 genotypes). There is no direct relationship between morphological and molecular diversity as genotypes those are grouped in same cluster on the basis of morphological diversity, grouped into different clusters on molecular diversity basis.
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Theses of M.Sc.