CORRELATION ANALYSIS BETWEEN LONGEVITY OF ADULT MOTHS AND ECONOMIC TRAITS IN FEW PURE RACES OF MULTIVOLTINE SILKWORM BOMBYX MORI (L)

Abstract

In silkworm breeding, numerous traits are considered as important for improving them to increase the benefits to silk producers. An attempt was made to correlate the lifespan of adult stage of silkworm Bombyx mori multivoltine races with the few yield parameters are found to be significant in deciding the next generation yield. The adult life span was correlated with larval weight, cocoon weight, shell weight, shell percentage and filament length in the six multivoltines. Based on the Pearson correlation co-efficient estimations, there is correlation between adult longevity and larval weight. There is strong correlation between adult longevity and three cocoon characters namely cocoon weight, shell weight and shell percentage. Insignificant correlations were observed among six races selected between adult life span and filament length. But the R2 values are on the lower side in the multivoltine. Three groups were identified among six multivoltines from the correlation studies. I group involves pre and npnd races with less R2 values where as II group includes C.nichi, Nistari and PM with moderate R2 values. However, Daizo race recorded highest R2 values. The results obtained in the present studies clearly demonstrates that there is significant correlation between adult longevity and four economic traits, larval weight, cocoon weight, shell weight, shell percentage. However for the trait filament length such correlation could be possible only among selected breeds/hybrids.