Genetic Diversity through D2 Analysis in Tomato (Solanum lycopersicum L.)
Shruthi Shimoga Prabhakar *
Department of Genetics and Plant Breeding, S.V. Agricultural College, Tirupati, Andhra Pradesh, India.
M. Shanthi Priya
Department of Genetics and Plant Breeding, S.V. Agricultural College, Tirupati, Andhra Pradesh, India.
B. Santhosh Kumar Naik
Department of Genetics and Plant Breeding, S.V. Agricultural College, Tirupati, Andhra Pradesh, India.
P. Karthik Reddy
Department of Horticulture, S.V. Agricultural College, Tirupati, Andhra Pradesh, India.
Posaboina Venkata Madhusudhan
Department of Genetics and Plant Breeding, S.V. Agricultural College, Tirupati, Andhra Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: Tomatoes rank as the second most important vegetable crop globally, following potatoes. The study was conducted to determine the genetic diversity among the tomato germplasm. Genetic diversity analysis helps identify distant parental lines that can be used to develop superior tomato varieties.
Study Design: Thirty tomato genotypes were assessed in a randomized block design with three replications.
Place and Duration of Study: The experiment was carried out at S. V. Agricultural College, Tirupati, during rabi 2023-24.
Methodology: The genetic diversity was determined by applying Mahalanobis D2 statistics.
Results: The thirty genotypes were divided into seven clusters. Cluster I was the largest cluster with eleven genotypes followed by nine genotypes in cluster II, four genotypes in cluster III, three in cluster V and only one genotype each in cluster IV, VI and VII. Beta-carotene content (39.77%) contributed the greatest towards genetic divergence, followed by the number of leaves at 60 DAT (34.02%), ascorbic acid (14.94%), yield per plant (6.67%) and titratable acidity (1.15%). Cluster III had the maximum intra-cluster distance. Highest inter-cluster distance was found between Cluster III and V.
Conclusion: Cross combinations between genotypes in Cluster III and V are hypothesized to lead to heterotic hybrids in F1 generation and some promising transgressive segregants in segregating generations.
Keywords: D2 analysis, genetic divergence, multivariate analysis, tomato