GENETIC VARIABILITY AND HERITABILITY AMONG MANDARIN (CITRUS RETICULATA BLANCO) GENOTYPES UNDER INDIAN SUB-TROPICAL CONDITIONS

Abstract

An effort has been made to study the genotypic variance, heritability, and genetic advance among nineteen mandarin genotypes grown under Indian sub-tropical conditions. The cluster analysis differentiated diverse genotypes which were grouped independently of their geographical origin. Wide variability in morphological characteristics indicated the genetic variability among mandarin genotypes. Rootstock diameter, scion diameter, fruit weight and seed weight showed a higher genotypic coefficient of variance, genetic advance and heritability, and genetic advance percentage of means. However, the phenotypic coefficient of variance was higher than the genotypic coefficient of variance for all the traits under study. The study indicated the existence of diversity in analyzed mandarin accessions. Furthermore, it concluded that the occurrence of additive gene action with low environmental influence is responsible for the determination of rootstock diameter, scion diameter, fruit weight, and seed weight as compared to other traits under study. Fruit yield was strongly correlated with the leaf lamina thickness and fruit weight followed by seed weight, indicating that fruit weight and seed weight can be used as selection criteria in an early year of bearing under crop improvement programme. Principal component analysis (PC1) distinguished positive correlations between fruit weight, fruit diameter, and fruit yield.