In the present study, 21 thermo tolerant tomato (Solanum lycopersicum L.) genotypes were evaluated to delineate the extent of genetic diversity through 10 quantitative traits. The genotypes were categorized into 4 distinct clusters using D2 statistics. Cluster IV had the maximum number (10) of genotypes, where all heat tolerant genotypes grouped together, followed by cluster I (5). Intra cluster analysis revealed that the cluster IV had highest distance, while the inter cluster distance was maximum between cluster III and cluster IV (6.53) indicating the presence of wide range of variability among genotypes of the cluster. Cluster IV recorded maximum cluster mean for yield (579.0), average fruit weight (33.33) and fruit set per cent (54.8) and the cluster III recorded highest mean value for days to 50 percent flowering (67.33). Principal component analysis showed that the first two principal components (PCâ€™s) accounting for 77.6 per cent of total variation. On the basis of inter cluster distance, cluster mean and principal component analysis observed in the present study, a crossing programme involving genotypes from cluster IV will be promising one for developing heat tolerant tomato hybrids.
Clustering pattern, D2 analysis, Genetic divergence, Principal component analysis, Solanum lycopersicum
Henareh, M., Dursun, A. and Mandoulakani, B.A. (2015). Genetic diversity in tomato landraces collected from Turkey and Iran revealed by morphological characters. Acta Scientiarum Polonorum. Hortorum Cultus., 14: 269-291.
Iqbal, Q., Saleem, M.Y., Hameed, A. and Asghar, M. (2014). Assessment of genetic divergence in tomato through agglomerative hierarchical clustering and principal component analysis. Pak. J. Bot., 46: 1865-
Mahalanobis, P.C. (1936). On the generalized distance in statistics. Proceedings of National Academic Science (India)., 2: 79-85.
Murthy, B.R. and Arunachalam, V. (1966). The nature of genetic divergence in relation to breeding system in crop plants. Indian J. Genet., 26: 188-189.
NHB (National Horticulture Board). (2015). [Available online]www.nhb.gov.in./area-pro/HB_Database_2015.
Rao, C.R. (1952). Advanced Statistical Methods in Biometric Research. John Willey & Sons, New York, USA. pp.357â€“363.
Reddy, B.R., Reddy, M.P., Begum, H. and Sunil, N. (2013). Genetic diversity studies in tomato (Solanum lycopersicum L.). J. Agric. Veterinary Sci., 4:53-55.
Rick, C.M. (1969). Origin of cultivated tomato, current status of the problem. Abstract XI, International Botanical Congress. pp.180.
Saleem, M.Y., Asghar, M., Iqbal, Q., Rahman, A. and Akram, M. (2013). Diallel analysis of yield and some yield components in tomato (Solanum lycopersicum L.). Pak. J. Bot., 45(4): 1247-1250.
Sharma, H.R., Sharma, D. and Thakur, A.K. (2006). Analysis of genetic divergence in tomato (Lycopersicon esculentum Mill.). J. Hort. Sci., 1(1): 52-54.
Singh, A.K., Sharma, J.P., Kumar, S. and Chopra, S. (2008). Genetic divergence in tomato (Lycopersicon esculentum Mill.). J. Res.,7: 1-8.
Singh, P.K. and Chaudhary, R.D. (1977). Biometrical methods in quantitative genetic analysis, Kalyani Publishers, New Delhi. pp.178-185.
Vavilov, N.I. (1951). The origin, variation, immunity and breeding of cultivated plant. Soil Sci., 72: 482.
This work is licensed under Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) © Author (s)