Application of stress susceptibility index and multivariate analysis of tomato (Solanum lycopersicum L.) to identify thermo-tolerant genotypes

Climatic parameters have become key mechanisms in controlling crop productivity worldwide. The more frequency of heat waves urges the breeding for thermo-tolerance. The motive of this study was to furnish an accurate and deep understanding on the heat tolerance of reproductive key traits (flowers with exerted stigma, pollen viability, fruits set per cent and number of fruits per cluster), along with earliness (days to first fruit set) and yield traits (average fruit weight, pericarp thickness, number of fruits per plant and yield per plant) in tomato. The study reasoned 35 genotypes employing three no-identical analysis tools, ANOVA of field assessment, stress susceptibility index and multivariate analysis based on genetic diversity. Insights of genetic architecture of the reproductive traits under heat stress might improve our core understanding, and might have applied value. The study substantiated the essence of heat tolerance for the genotypes EC-620395, EC-620401, EC-620406 and EC-620410. Divergence analysis revealed five clusters corresponding to specific characters. Therefore on the ground of the investigation new breeding lines and breeding strategies can be implemented under changing environmental conditions with special reference to elevated temperature.