• International Journal of Industrial Entomology and Biomaterials
• /
• 제7권2호
• /
• pp.221-229
• /
• 2003

Ten multivoltine female parental lines were crossed with popular bivoltine male silkworm breed NB$_4$D$_2$. Three types of heterosis parameters viz., heterosis over mid-parental value (hybrid vigour), heterobeltiosis (useful heterosis) and standard heterosis (standard check) were estimated for 15 economically important quantitative traits. The interaction among the hybrids and parents indicated significant effect for maximum characters. The heterotic effect of new hybrid combination was compared with popular hybrids viz., Pure Mysore${\times}$NB$_4$D$_2$ and Nistari${\times}$NB$_4$D$_2$. Varied heterotic effect was observed for different traits for different hybrid combination. The results inferred that the crosses viz., BL$_{23}$${\times}$NB$_4$D$_2$ ranked top for 14 traits followed by Hosa Mysore${\times}$NB$_4$D$_2$ for 11 traits; PA$_{12}$${\times}$NB$_4$D$_2$ for 9 traits; BL$_{24}$${\times}$NB$_4$D$_2$ for 8 traits; Kolar Gold${\times}$NB$_4$D$_2$ for 7 traits; WAI$_1$${\times}$NB$_4$D$_2$ for 6 traits and MU$_{11}$${\times}$NB$_4$D$_2$ for 5 traits. Among these, the best hybrids Kolar Gold${\times}$NB$_4$D$_2$ and MU$_{11}$${\times}$NB$_4$D$_2$ were identified for longer filament length and fine denier. Similarly for higher cocoon yield and silk productivity BL$_{223}$${\times}$NB$_4$D$_2$ and BL$_{24}$${\times}$NB$_4$D$_2$ were found to be superior. These hybrid combinations are suitable for commercial exploitation at large scale.e.e.e.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제8권2호
• /
• pp.189-194
• /
• 2004

Amylase isozyme based three multivoltine viz., N+p, Np, N+ $p^{cho}$ and two bivoltine-D6+p, D6p syngenic lines (Syn. L) were developed from germplasm (GP) stocks Nistari (N) and D6 respectively. haemolymph isozyme pattern at pH 7.0 and 8.5 depicted a total 11 number (Am $y_{1 to 6}$ at pH 7.0 and Am $y^{l to 5}$ at pH 8.5) of native proteins (NP) of various sizes are amylase isozyme expressers. Among eleven NPs, two NPs of 770 kDa (Am $y^{6}$ at pH 7.0) and 376 kDa (Am $y^3$ at pH 8.5) are $\alpha$-amylase expressers and remaining NPs of 370, 364, 350, 329 and 274 kDa at pH 7.0 and 206, 292, 416, 725 kDa at pH 8.5 are $\beta$-amylase expressers. Accordingly, digestive juice amylase isozyme pattern at aforesaid pH also depicted a total number of 10 NPs (Am $y^{1 to 5}$) at each pH 7.0 and 8.5 are amylase expressers of which NP of 387 kDa (Am $y^4$ at pH 7.0) and 780 kDa (Am $y^{5}$ at pH 8.5) are a-amylase expresser. Remaining NPs of 338,297 ＆ 216 kDa at pH 7.0 and 370, 341, 329 ＆302 kDa at pH 8.5 are $\beta$-amylase expresser. Recurrent backcross lines (RBL) viz., N+pRBL and NpRBL were developed through introgression of high shell weight character (a multigenic trait) to be used further for congenic line (Con. L) development and to understand any association with introgressed character. Isozyme pattern in haemolymph of RBLs depicted only one $\alpha$-amylase of 770 kDa at pH 7.0 and 376 kDa at pH 8.0 with three and four respective $\beta$-amylase bands but in bivoltine lines numbers of $\beta$-amylase bands vary between 1 to 2 at aforesaid pH. Variability was also observed in digestive juice of multivolitine and its RBLs but bivoltine lines express null activity at both pH except appearance of one very week $\alpha$-amylase band D6+p at pH 8.5. Overall study suggests that not a single NP at both pH is common for expression of any band of amylase isozyme i.e., a totally different set of proteins are the amylase isozyme expresser at specific pH and no molecular factor of amylase is associated in developed RBLs which showed improvement on survival, single cocoon shell weight (SCSW) and single filament length over receptor parents.s.s.s.