Investigation on intera-specific biodiversity of 20 silkworm germplasm based on glucose, urea, uric acid, lactat D-hydrogenase, total protein and alpha amylase

Abstract

The aim of this experiment is to investigate the profile of biochemical markers in 20 Iranian silkworm cocoon germplasm. On the fifth day (fifth instar), heamolymph was sampled using a standard method. The sampled heamolymph was transferred to the laboratory. The heamolymph was obtained by cutting the abdominal proleg of the silkworms and collecting the heamolymph in a 1.5 ml tube containing a few granules of phenylthio urea to prevent melanization. After 10 min of centrifugation at 10000 rpm, the supernatant was collected. Pellets were then discarded, and the supernatant was transferred into new tubes that were preserved at -20oC until the onset of the experiments. From the results obtained, it was observed that the amount of glucose in the 20 varieties of silkworm studied ranged from 1.00 to 14.04 mg/dl. Among the varieties studied, the highest level (14.04 mg/dl) of glucose was obtained from (2029) 113, while the lowest level (1.00 mg/dl) of glucose was obtained from the varieties 153 (Xihang-1), M2-6-18 (109), 151 (103×M-1-1), Xihang 2/3, and M-1-1×103. The amount of glucose obtained from the other varieties was between these two groups of values (14.04 and 1.00 mg/dl). The statistical differences between the varieties studied for this trait were significant (P<0.05). Based on dendrogram analyses, the varieties analyzed were divided into two distinct groups. At cross 1.76, two clusters were formed which were classified into subgroups at crosses 1.30 and 0.80. Frequent divisions were also observed in the major groups. The first group included (2029) 113 variety, while the second group included other varieties. Among the varieties studied, the highest level (6.52 mg/dl) of total protein was obtained from K-107; M2-6-18 variety had a total protein value of 4.11 g/dl which was lower than that of all the other varieties (P<0.05). Dendrogram analyses also revealed that the varieties were divided into two distinct groups. At cross 3.11, two clusters were formed which were classified into subgroups at cross 0.02. Frequent divisions were also observed in the major groups. The first group included the variety 151, while the second group included other varieties. Key words: Dendrogram, cluster, Bombyx mori, lactat D-hydrogenase, heamolymph.