Heat stress tolerance study in eggplant based on morphological and yield traits

Abstract

High temperature has detrimental effects on growth and yield of any crops. A total of 62 two eggplant genotypes were evaluated for growth and yield traits at two growing season during summer season (March-July) and kharif season (July-November). Average of three replications was used for each trait in statistical analysis involving one way analysis of variance (ANOVA), Principal Component Analysis (PCA) and Agglomerative Hierarchial Clustering (AHC) using SAS ver. 9.3 and R package. Analysis of variance indicated high variability for all the traits among the eggplant genotypes. Highest yield per plant was recorded in Guhala Chatua Local (1.8 kg) in summer season whereas in kharif season, yield per plant was maximum in Swarnamani Black (5.97 Kg). The mean yield per plant (1.83 kg) was more in kharif season as compared to summer season (0.09 kg). The percentage yield reduction in summer season was more than 90% in almost all the genotypes and the lowest yield reduction (22.11%) was found in Guhala Chatua Local followed by DBL-21 and DBL-08. In summer season, the first principal component (PC1) and second principal component (PC2) could explain 48% and 14% of total variance, respectively where yield per plant contributed positively to PC1. In kharif season, first principal component (PC1) and second principal component (PC2) could explain 33% and 20% of the variance, respectively where total number of fruit weight per plant, fruit diameter and yield per plant traits contributed positively to PC1. The Hierarchical cluster analysis revealed five clusters based on the similarities among the genotypes in both summer and kharif season but the clustering pattern was different among season. Based on the study, promising heat-tolerant genotypes (Guhala Chatua Local, DBL-21 and DBL-08) have been identified which could be novel source for heat tolerance gene (s) for utilizing in breeding programme.