Genetic divergence analysis in Ailanthus excelsa based on morphological traits

Abstract

Knowledge about the extent of source variation in relation to growth and fodder yield characters is very useful for improvement of multipurpose tree species (MPTs). The present studies were conducted to assess the variability among 23 progenies of Ailanthus excelsa for its further improvement. Morphological and genetic analyses were used to identify the elite progeny and record the variations in different progenies of A. excelsa. Significant differences (P >0.05) were recorded among the progenies of A. excelsa for growth and fodder yield characters. Maximum diameter 15.33 and 86.11 mm was recorded in progeny P23 after 6 and 12 months of planting. The genotypic coefficient of variation was much less than the phenotypic coefficient of variation for growth characters, i.e. height, diameter and volume index indicating the influence of environment on growth. Maximum phenotypic coefficient of variation (53.98) and genotypic coefficient of variation (31.16) were observed for volume index. High heritability values for leaf fodder yield (67.00%) and height (64.00%) was observed, while low heritability was observed for height and diameter. The genetic advance as per cent of mean varied from 4.63 to 47 .31 % (leaf fodder). Plant height and diameter after 12 months of planting showed positive correlation with each other and fodder yield. Progeny P23 showed consistency in terms of growth and found superior over others. Non Hierarchical Euclidean cluster analysis (D2), of 23 progenies grouped the progenies into 4 clusters. The intra and inter-cluster distance indicated the presence of wider genetic distance between A. excelsa progenies. Maximum inter-cluster distance between cluster II and IV (3.93) followed by cluster III and IV indicates greater divergence between genotypes belonging to these clusters and an attempt to cross the genotypes in these clusters should bring out desirable gene combinations. Among the growth attributes, volume index contributed maximum to genetic divergence.