IMPROVEMENT OF FECUNDITY IN POPULAR SILKWORM BREEDS OF BOMBYXMORI L THROUGH DIRECTIONAL SELECTION

摘要

Factors contributing for the total yield are to be given prime importance by the silkworm breeders during the course of breeding. Among many yield contributors fecundity plays a pivotal role. Higher the fecundity, more will be the number of larvae resulting in higher cocoon yield. Improvement in one character automatically enhances the total outcome. Hence, the need for the improvement in fecundity in popular silkworm breeds was realized and the present study on the directional selection for higher pupal weight in females of CSR2, CSR2 (SL), CSR4 and crossing with high cocoon shell percentage males for four generations continuously resulted in the. maximum improvement in fecundity in the 3rd generation of CSR2 (SL) and CSR4 and in the 2nd generationof CSR2. The selected breeds excelled in fecundity when compared to the control and all the other metric traits were at par with the control. The method followed for the improvement of fecundity in popular breeds is discussed.