Abstract:In order to amalgamate the effects of nutrition and its efficiency on genetic traits expression in silkworm germplasm breeds by serial analysis on nutrigenetic traits and utilized as biomarker with an aim to identify nutritionally efficient silkworm germplasm breeds. In the present study, six bivoltine silkworm breeds were subjected for investigation on ingestion, digestion and utilization of dry food matter in single silkworm larva and its sharing on economically important stages larva, cocoon and shell weight in 5th stage. It was resolved that low consumption with high conversion efficiency of food ingested in silkworm breeds on nineteen nutrigenetic traits analyzed by standard gravimetric method with the aid of INDOSTAT software to understand the nutrigenomic divergence among the silkworm germplasm breeds against different seasons. Results indicated that higher conversion efficiency was observed in most of the new silkworm breeds for Efficiency of Conversion of Ingesta (ECI) to cocoon and shell than control (APS ) as leaf -cocoon and leaf-shell conversion 8 are the ultimate indices in nutrigenomic analysis. It also demonstrated that relatively smaller amount of Consumption Index (CI), respiration, Metabolic Rate (MR) with superior Relative Growth Rate (RGR) and in relation to quantum of food ingesta and digesta requisite per gram of cocoon and shell found less than the control. This concluded that nutrigenetic traits directly associated to the quantum of food ingesta and digesta gG of cocoon and shell and such nutrigenetic study pragmatically utilized as biomarkers in order to 1 advocate sturdily the following breeds viz., RBD , RBD (peanut type cocoon), RBO , RBO (oval type cocoon) 1 4 2 3 were chosen as highly nutritionally efficient bivoltine silkworm germplasm breeds.

In the present study, polyvoltine germplasm stock of Andhra Pradesh State Sericulture Research and Development, Institute (APSSRDI) was evaluated for its performance based on quantitative and qualitative traits. Twenty-one oval and 10 peanut cocoon shaped lines were reared in different seasons of the year. Since the polyvoltines are non-diapausing, six generations were reared and evaluated for various economically important traits based on evaluation index and sub-ordinate function statistical methods. Ten top ranked lines obtained by using both the methods were identified as potential parental strains. Among oval lines, APM14, APM11, APM18, APMW9, and APM19, and among peanut lines APMD5, APMD1, APMD3, APMD9 and APMD8 were selected as base material. The identified high yielding lines will be used in various breeding programmes as initial parents for the synthesis of superior polyvoltine breeds/hybrids.

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Boil-off loss ratio is one of the most important economic traits to be considered during the course of silkworm breeding. The boil-off loss ratio varies among the breeds and seasons.The present study was undertaken with 5 oval and 5 peanut breeds and twenty five hybrids involving these parents to select the promising hybrids with desired boil-off loss ratio. Accordingly, studies were undertaken to estimate the heterosis and heterobeltiosis. It was observed that majority of the hybrids revealed negative heterosis for boil-off loss ratio which is desirable. Based on the heterosis and heterobeltiosis, among all the hybrids, the hybrid APBRO5 x APBRD5 exhibited highest negative heterosis for boil-off loss ratio and also exhibited highest EI value (64.5) for the quantitative and qualitative traits. Based on the hybrids performance, boil-off loss ratio, heterosis and heterobeltiosis and evaluation index, the hybrids viz. APBRO5 x APBRD5, APBRO1 x APBRD1 and APBRO3 x APBRD4 were identified for commercial exploitation. IntroductionTo face the global competitiveness in silk production there is a need to improve the quality of the raw silk and as such the sericulture industry requires good quality of silk to produce internationally gradable silk fabric to meet the requirement of the consumers across the world resulting in increased foreign exchange. To meet the specific requirement of the silk industry, the silkworm breeders have developed various hybrids such as productive breeds, robust breeds, breeds with special traits and sex limited races etc. Keeping this in view, most of the silkworm breeders have been concentrating on boil-off loss ratio to produce good quality silk as the boil-off loss ratio is one of the most important qualitative trait in silkworm breeding. The silkworm Bombyx mori L. spins a shell by extruding silk bave at the end of its larval period. The silk bave is composed of two silk proteins namely fibroin and sericin and also contains a small quantity of fatty, waxy, colouring and mineral matters. The fibroin protein occupies the middle portion of the Boil-off loss ratio in newly developed bivoltine silkworm hybrids 14 separation and assessment, 60 cocoon shells (30 each of female and male) were selected from each breed/ hybrid separately. Three replications were maintained each having 10 males and 10 females for conducting the experiment. Degumming was carried out by boiling the cocoon shells in soap solution using a standard procedure (Basavaraja et al., 2000). Two step boiling method as explained below was employed for the degumming of the cocoon shells and used neutral liquid soap for boiling. A quantity of 7g soap was dissolved in 1 liter of water for degumming and the material: liquor ratio was maintained as 1:40. First degummingThe liquor solution of the soap and soda was boiled in a copper vessel. When the boiling media solution reached the boiling point (>90 o C), the cocoon shell sample bags were immersed completely in boiling media kept tightly closed for 40 minutes. At an interval of 10 m...

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