Gut Enzyme Activity in Reciprocal Crosses of Tropical Tasar Silkworm Antheraea mylitta D during F1 Larval Stage

Antheraea mylitta D, tropical tasar silkworm is basically a species which exhibits variability through its ecoraces, as such it seems to be potentially a good material for the exploitation of heterosis. Genetic variability is pre-requisite of any breeding programme for improvement of quantitative characters and amount of variability existing in the population is of paramount importance in selection practices to study the diversity in the population. In the present study, three reciprocal crosses with six combinations were prepared such as semi-domestic Daba (S-d) x Laria, Laria x Daba (S-d), Daba (wild) x Daba (S-d), Daba (S-d) x Daba (wild), Laria x Daba (wild) and Daba (wild) x Laria. The quantitative analysis of some digestive enzyme activity such as amylase, protease and alkaline phosphatases was carried out in the 5th Instar F1 larval midgut tissues of different combinations. Significantly higher (at p<0.05) enzyme activity was recorded in the F1 of Daba (Sd) xDaba (wild) combination and relatively lower activity was noticed inthe Daba(S-d) x Laria combination. Highly variable protease activity was recorded in different combinations studied. Alkaline Phosphatase activity was higher in the Laria x Daba (S-d) compared to other batches of tasar silkworm F1 larvae. Sexual dimorphism in the enzyme activity was very much apparent. The study infers the high degree of variability in different populations of Antheraea mylitta could be instrumental to exploit heterosis effect in important quantitative and qualitative traits. Biochemical genetics particularly the enzyme studies can be a viable tool for the assessment of variability in population, inter-ecoracial and cross breed polymorphism in tropical tasar silkworm.