• International Journal of Industrial Entomology and Biomaterials
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• 제11권2호
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• pp.119-124
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• 2005

To determine the level of heterosis, higher cocoon shell weight multivoltine congenic lines (Con. L) and bivoltine syngenic lines (Syn. L) of silkworm were used for crosses. First filial generations $(F_1s)$ expressed heterobeltiotic genetic interaction at significant magnitude (p < 0.01) for single cocoon shell weight (SCSW). The other linked characters viz., single cocoon weight (SCW) and yield by weight per 10, 000 larvae were also significantly higher (p < 0.01) than the better parental lines. All the hybrids showed significant improvement for these aforesaid characters over standard heterosis (Standard check). The reeling parameters viz., filament length, raw silk, neatness, cohesionstrokes etc, also showed improvement among the hybrids than check in congenial environment. Overall results suggested that the cross between congenic and syngenic lines provide better heterosis with good quality silk than conventional hybrids and may be used for commercial exploitation.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권1호
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• pp.21-27
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• 2003

Manifestation of heterotic genetic interaction was studied in different hybrids made between multivoltine recurrent backcross (RBL)/congenic lines (Con. L) during unfavourable season when temperature and relative humidity are > $30^{\circ}C$ and 86%, respectively. A few number of silkworm race or strain or breed like Nistari (N ＋ p or Np) can sustain the temperature above 3$0^{\circ}C$ and RH above 86%. The present heterosis study screened a hybrid i.e., CB$_{5}$Lm5RBL1M$_{6}$DPC-LmE$^1$RBL and its reciprocal provided heterobeltiotic effect on survival by number and pupation rate at a magnitude of 20% (p < 0.01) and yield by weight of 10% (p < 0.01). Beside all the hybrids expressed heterosis over check - Nistari (N ＋ p) with better quality silk. Therefore, aforesaid hybrid may be useful for utilization at commercial level during adverse seasons of West Bengal.gal.