BIOCHEMICAL PROFILES OF DIFFERENT BREEDS OF Bombyx mori ANTAGONIZED WITH FUNGAL PATHOGEN Beauveria bassiana

The silkworm, Bombyx mori has been well exploited as a model for the wide range of research investigations and a typical representative of lepidopteran insects. The silkworm is a primary producer of mulberry silk with a great commercial significance. Silkworms are very delicate and susceptible to various pathogenic - microbial organisms that affect the productive parameters of the silk cocoons. The degree of susceptibility varied from breed to breed. Biochemical traits indicate the physiological status of an organism and may direct the prospect of using biochemical markers to assess the health condition of the silkworm breeds. Further Beauveria bassiana the fungal pathogen confined to haemolymph till the death of the host organism. Therefore, appropriate understanding of biochemical interactions and physiological manipulations in the haemolymph between host and pathogen in response to infection is obligatory before stepping into other research areas like immunology and management of disease. With this backdrop, dynamics of vital macro-molecules were examined in the haemolymph of 5th instar under stress conditions caused by fungal pathogen Beauveria bassiana in three popular silkworm breeds viz., bivoltine double hybrid (CSR 2 x CSR 27) x (CSR 6 x CSR 26), crossbreed (PM × CSR2) and bivoltine single hybrid (CSR2 X CSR4). Significant variations were noticed in three major biomolecules chosen for the study such as total carbohydrates, proteins and Lipids in three different breeds, the encouraging results were recorded in bivoltine double hybrid followed by crossbreed and bivoltine single hybrid. Results of the study revealed that bivoltine double hybrid is superior compared to crossbreed and bivoltine single hybrid in all the biochemical parameters evaluated. The outcome of the study can be used for screening and to differentiate the silkworm breeds.