Genetic studies on variability, heritability, genetic advance and cluster analysis in pear (Pyrus spp.)

Data on 21 quantitative traits were subjected to genotypic and phenotypic coefficient of variation, heritability, genetic advance and clustering using D² analysis with group constellation following Tocher's method. Phenotypic and genotypic coefficients of variation were high for fruit yield (46.58 and 46.55%), fruit length (47.06 and 42.69%) fruit weight (46.53 and 45.17%), pedicel length (38.47 and 37.82%) and TSS (39.62 and 36.1%) and medium to low for other traits. The estimates of heritability and genetic advance were maximum for fruit yield. High heritability estimates accompanied with greater genetic advance were observed for yield, fruit weight, pedicel length and fruit length indicating that these traits may be considered for selecting promising parents. Test genotypes were grouped into four clusters with maximum number of genotypes (6) in cluster I, 2 genotypes in cluster IV and one genotype each in clusters II and III. Highest inter-cluster distance (153.05) was between cluster II and IV, while highest intra-cluster distance was observed in cluster IV (36.24).