BIOCHEMICAL CHANGES DUE TO INFECTIOUS FLACHERIE VIRUS INFECTION IN THE HAEMOLYMPH OF POPULAR MULTIVOLTINE SILKWORM BREEDS

Though India ranks second in silk production (18,760 MT) next to China (57,230 MT), the average Cocoon yield in India is very low primarily due to high disease incidence. Silkworm diseases are prevalent throughout the year and the incidence differs significantly between seasons. Infectious flacherie of silkworm is caused by Bombyx 11701i Infectious flacherie virus (BmIFV). WV produces a typical morphological symptom in diseased larvae, spreads in silkworm populations at an alarming rate and causes severe crop loss. Understanding the physiological changes in the haemolymph of diseased larvae is important to advocate propalytic measures against the disease. The present study revealed that the total protein content in haemolymph in Pure Mysore on the lsiclay of 5thinstar was 9.89 mg /m1 and increased up to 15.00 mg / m by 6th day in the control batch. In case of treated larvae of Pure Mysore, it was 8.31 mg / ml on first day and reached maximum by 8.73 mg / ml on fourth day. In case of C. Nichi, the total protein content on the 1st day of 5th instar was 10.19 mg / ml and increased up to 19.21 mg/ml. In the case of treated batches it was 9.01 mg / ml on first day of fifth instar and reached to 17.04 mg / ml. The total protein content in Nistari was 13.92 mg /m1 and increased up to 16.88 mg / ml in the control batch by 6th day and it is 7.44 mg/ml and reached maximum by 14.69 mg/ml on 5th day in treated batch. In case of ND7 the protein content was 11.06 mg / ml and increased up to 19.16 mg / ml and treated batches, the total protein was 11.00 mg / nil on first day of fifth instar and reached to 15.04 mg / ml on fifth day and there is no consistency. The total carbohydrate content in haemolymph during the course of infection in Pure Mysore increased steadily from 3.399 mg/ml on 1 day of fifth instar to 5.434 mg/ml on the final day of fifth instar. In the C. Nichi it is increased steadily from 3.048 mg/ml on first'day of fifth instar to 13.260 mg/nil on 6th day of final age. In BmIFV treated larvae of C. Nichi, the total carbohydrate content of the haemolymph has drastically reduced.The results indicated that total lipid content in the haemolymph of control breed Pure Mysore, C. Nichi, Nistari and ND7 increased from first day of fifth instar to the final day of fifth instar. The total lipid content is not constant in treated batches except in C. Nichi, which is a tolerant breed.