IMPROVEMENT OF FECUNDITY IN POPULAR SILKWORM BREEDS OF BOMBYX MORI L. THROUGH DIRECTIONAL SELECTION
K.K. SIJARMILA *
CENTRAL SER1CULTURAL RESEARCH AND TRAINING INSTITUTE, MYSORE-570 008, INDIA.
G.V. KALPANA *
CENTRAL SER1CULTURAL RESEARCH AND TRAINING INSTITUTE, MYSORE-570 008, INDIA.
*Author to whom correspondence should be addressed.
Abstract
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 maies for four generations continuously resulted in the maximum improvement in fecundity in the 3’’ generation of CSR2 (SL) and CSR4 and in the 2 generation of 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. .
Keywords: Bombyx mon Directional selection, pupal weight, cocoon shell percentage and fecundity