Correlations between some economic larval traits of silkworm

Abstract

Abstract. Silkworm, Bombyx mori L. is an economic insect that has great importance on cocoon and silk production. The development of sericultural industry depends on quality and yield in terms of qualitative and quantitative silkworm characters. Mature larval weight and silk gland mass are important factors in silkworm breeding. Silk gland mass has significant impact on the synthesis of silk protein in fifth larval stage. The investigation was conducted to evaluate the correlations between silk gland mass and mature larva weight of M and ZF (China), and N and ZB (Japan) lines and their hybrids MxN, ZFxZB. In this research, silkworm lines and hybrids were reared at the laboratory with 600 silkworm larvae for each four lines and their hybrids to determine these silkworm traits. Analysis of variance indicated that the mean values in Chinese lines and hybrids were found to be significant (P<0.01) for mature larva weight. On the other hand, mean value of silk gland mass was determined as important for Chinese, Japanese lines and hybrids (P<0.01). Both mature larva weight and silk gland mass have positive correlation in Chinese lines (r=0.659) and hybrids (r=0.643) (P<0.01). Otherwise, the correlation between these characters were not found to be significant for Japanese lines. As a result, it is necessary to search the correlation between different characters and to protect the genetic diversity in silkworm lines.