Impact of Methionine and Tryptophan Supplementation on Silk Gland Weight and Tissue Somatic Index in Eri Silkworm (Samia ricini Donovan)
A. Hazarika
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
P. R. Narzary *
Department of Sericulture, Forest College and Research Institute, Tamil Nadu Agricultural University, Mettupalayam, Tamil Nadu – 641 301, India.
M. Saikia
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
H. Saikia
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
Shilpa Saikia
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
A. Rajkhowa
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
B. Kashyap
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
A. A. Sangma
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
S.Saikia
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
S.D. Borah
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
R.R. Saikia
Department of Sericulture, College of Agriculture, Assam Agricultural University, Jorhat-785013 (Assam), India.
*Author to whom correspondence should be addressed.
Abstract
This study evaluated the impact of methionine and tryptophan supplementation on the silk gland weight and Silk Gland Tissue Somatic Index (SGTSI) of eri silkworm, Samia ricini Donovan, a key species in vanya silk production. Freshly collected castor leaves were fortified with methionine and tryptophan solutions at various concentrations and fed to silkworm larvae from the third instar until maturity. The treatments significantly enhanced silk gland weight and SGTSI compared to the control. The highest silk gland weight (1.52g) and SGTSI (25.16%) were observed in larvae fed with tryptophan at 500 ppm (T6), followed by methionine at 500 ppm (T3) with 1.47g and 24.61%, respectively. Control larvae exhibited the lowest values (1.07g and 19.43%). Combination treatments of methionine and tryptophan showed less improvement compared to individual treatments. These findings suggest that dietary supplementation with specific amino acids could enhance silk gland development and silk production.
Keywords: Castor, eri silkworm, methionine, Samia ricini Donovan, silk gland, tryptophan