Estimation of Genetic Diversity Using D\(^2\) and PCA in Brinjal (Solanum melongena L.)

Abstract

The current investigation was carried out on brinjal (Solanum melongena L.) during autumn winter season 2021 -2022 with the aims to study the genetic diversity with the help of D2 and principle component analysis. The experimental material for study consisted of 38 genotypes including one check (NDB-2) and laid out in Completely Randomized-Block Design with three replications. Based on D2 the genotypes were grouped into seven different non-overlapping clusters. Cluster I had highest number of genotypes (23) followed by cluster II (10) and cluster III, IV, V, VI and VII (1). The maximum inter-cluster distance was observed between cluster III and VII. Maximum percent contribution in genetic divergence was showed by fruit circumference, TSS, number of primary branches per plant and minimum contribution by fruit yield per plant. Based on the PCA with 13 traits, it formed 6 principal components (PCs) with more than 1 Eigen value apart from PC6 (0.80). These components indicated maximum variation among the variables with a diversity percentage of 79.30 per cent. The first PC showed 23.43 per cent variation, while the second, third, fourth, fifth and sixth PCs showed the variation of 16.89 per cent, 14.11 per cent, 10.37 per cent, 8.31 per cent and 6.17, respectively. Therefore, the traits coming under the 6 PCs manifest a high degree of genetic variation and they add up the genetic diversity between the genotypes which could be exploited in crop improvement programmes. Thus, there is a great potential for effective crop modification for improved yield and yield-attributing traits in present brinjal germplasm.