Genetic Divergence Studies for Yield Component Traits in Genome-wide Association Mapping Panel of Tomato (Solanum lycopersicum L.)

Author: Maheshkumar B. Doddamani, B. Fakrudin, M. Anjanappa, M. Prashanth, H.C. Krishna and S. Mohan Kumar

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Abstract

Genetic diversity is key factor for any crop improvement. Genetic diversity, its nature and its degree are useful for selecting desirable parents from a germplasm collection for development of superior hybrids and for successful breeding programme. In this study accessions of genome-wide association mapping panel of tomato were assessed for their genetic divergence using Mahalanobis D2 statistics. Genetic divergence studies revealed considerable genetic diversity among 264 accessions of tomato for a set of eleven quantitative traits pertaining to the earliness, growth and yield viz., plant height (cm), number of branches per plant, days taken to 50 % flowering, number of clusters per plant, number of fruits per cluster, number of fruits per plant, average fruit weight (g), number of locules per fruit, fruiting duration (days), fruit diameter (cm) and total yield per plant (kg). Analysed 264 tomato accessions grouped into 11 distinct clusters depending upon the similarities of their D2 values following Tocher’s method. Considerable diversity within and between 11 clusters was observed among the accessions. The characteristics such as average fruit weight, fruit diameter and number of locules per fruit were the potent factors in differentiating the accessions of tomato studied. The use of diverse genotypes from the clusters with high inter-cluster distance, such as cluster XI and VIII, XI and II and XI and VII in hybridization is expected to result in high heterosis and throw desirable transgressive segregants in the segregating generations that can form potential pre-breeding material for the improvement of tomato crop.

Keywords

Genetic divergence, Yield Component Traits, Genome-wide Association Mapping Panel Tomato

Conclusion

Among the various methods identified/developed to study the genetic divergence in the genotypes, Mahalanobis D2 (Mahalanobis, 1936) is reliable and the most frequently used. D2 analysis is a useful tool in quantifying the degree of divergence between biological population at genotypic level and to assess relative contribution of different components to the total divergence, both at the inter and intra-cluster levels. Thus, from the present investigation it can be concluded that genotypes of cluster XI and VIII, XI and II and XI and VII are complementary for maximum traits and could be selected for hybridization to develop promising F1 hybrids or transgressive segregants in succeeding generations. To improve maximum yield per plant, clusters IX, V and II are an ideal combination for three way cross or their derivatives for future selection.

References

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How to cite this article

Maheshkumar B. Doddamani, B. Fakrudin, M. Anjanappa, M. Prashanth, H.C. Krishna and S. Mohan Kumar (2022). Genetic Divergence Studies for Yield Component Traits in Genome-wide Association Mapping Panel of Tomato (Solanum lycopersicum L.). Biological Forum – An International Journal, 14(4): 1278-1282.