Genetic diversity and classification of 51 strains of silkworm Bombyx mori (Lepidoptera: Bombycidae) germplasm based on larval phenotypic data using Ward’s and UPGMA methods

Abstract

The aim of this experiment was to study and classify all 51 pure lines of Iran silkworm germplasm based on larval traits and identification of pure lines relationships. The average linkage between two groups is considered as the average of distance between all pairs of cases with one number from each group. Hierarchical clustering analysis was carried out by considering all studied parameters together. The grouping methods allowed the study to subdivide the observations into several subgroups in such a way that homogeneity was obtained inside the subgroups and heterogeneity among the subgroups. Various methods generated similar dendograms. On the basis of these dendrograms, analyzed strains were divided into 2 distinct groups. Frequent divisions were also observed in major groups. The first group was divided into two sub groups including three and eight strains, respectively. The second major group was divided into two sub groups which include 4 and 36 strains, respectively.

Key words: Silkworm, unweighted pair-group method using arithmetic average (UPGMA), ward, cluster, gene bank, Iran.