SEASONAL VARIATION IN COCOON SIZE IN POLY VOLTINE x BIVOLTINE HYBRIDS OF THE MULBERRY SILKWORM, BOMBYX MORI L.
RAVINDRA SINGH *
REGIONAL SERICULTURAL RESEARCH STATION. JOR HAT -785 005, INDIA
NAZIA CHOUDHARY *
CENTRAL SERICULTURAL RESEARCH & TRAINING INSTITUTE MYSORE - 570 008, INDIA
RANUMA DAS *
REGIONAL SERICULTURAL RESEARCH STATION. JOR HAT -785 005, INDIA
*Author to whom correspondence should be addressed.
Abstract
Thirty six F, hybrids involving six poly voltine namely, BL, BLs. 96A, 96E, PM and 96H and six bivoltine breeds viz. CSR, CSR, CSR, CSR. CSR, and NBD, of the silkworm, Bombyx mori L, were evaluated for cocoon size variability during pre-monsoon (March- April, 2008), monsoon (August-September 2008) and post-monsoon (December- January. 2008-09). Results indicated great deal of variation in cocoon size in different hybrids in different seasons. Four poly Voltine x bivoltine hybrids namely, BL, X CSR BLos X CSR 7. BLos X CSR, and 96AX CSR were found to possess uniform cocoons in all the three seasons on the basis of standard deviation. The short listed hybrids can be exploited commercially to increase quality silk production.
Keywords: Cocoon size variability, coefficient of variation,, poly Voltine x bivoltine hybrids, seasonal variation, Standard deviation.