Principle component and cluster analysis for heat tolerance in tomato under open condition for yield and seed production

The nature and magnitude of genetic divergence of 76 genotypes of tomato under heat stress in open condition was estimated using R-Studio. The genotypes under the study showed considerable amount of diversity for all the traits. The first three components of Principle Component Analysis (PCA) explained the maximum variability present among the traits studied (40 percentage of total phenotypic variability). The PC1, PC2 and PC3 components were responsible for 16.63, 11.53 and 11.05% of phenotypic variability, respectively. Based on the diversity analysis the genotypes under investigation were divided into four diverse and genetically distinct clusters. Cluster-1 (50) and Cluster-4 (19) had majority of genotypes under them whereas Cluster-2 (2) and Cluster-3 (5) had smaller number of genotypes under them. The study concluded that the genotypes used had considerable amount of phenotypic-variability for heat tolerance under open condition for yield as well as seed production. The traits such as yield per plant, seed yield per plant, number of fruits per plant, titratable acidity, and plant-height contributed a major portion to the phenotypic-variability among all the traits in this study for heat-tolerance.