Genetic variability and heritability of chickpea (cicer arietinum L.) genotypes in normal and elevated temperatures
There has been rising interest in growing chickpea among other legumes for food due to its endurance to harsh weather conditions. However, rising temperatures due to climate change may tend to affect the growing regions leave alone limiting its expansion. Chickpea is fairly drought tolerant, but high temperatures reduce yield substantially. It's therefore imperative to breed for high temperature tolerance. Field experiments were carried out at Kabete (cool environment) and Kiboko (hot environment) to establish the genetic variability and heritability of over 110 chickpea genotypes. Phenological and morphological traits, and yield data were recorded. The data was subjected to analysis of variance, correlation analysis, path coefficient analysis and principal component analysis to establish variability. Heritability estimates were also computed. Significant difference showed that there was genetic variability in most traits at both sites. Path coefficient analysis showed that number of pods per plant had the highest direct effect on grain yield (0.266 and 0.320 for Kabete and Kiboko respectively) in both locations. Scatter diagrams from principal component analysis at Kiboko separated the genotypes into distinct groups (less susceptible, moderately susceptible and highly susceptible) but there was no distinct grouping at Kabete. No tolerant genotypes were identified for growing in areas with high temperatures experienced throughout the growing season. Heritability estimates were high for days to 50% flowering (Kabete; 0.8 and Kiboko; 0.6), days to 75% maturity (Kabete; 0.5 and Kiboko 0.6) and 100 seed mass (Kabete; 0.9 and Kiboko; 0.7) hence these characters can be effectively improved through selection. Presence of genetic Variations makes breeding for high temperature tolerance feasible. Earliness in flowering and maturity are important traits to select for while breeding for high temperature tolerance.