Comparative performance of SL-KSPM, a sex-limited polyvoltine race and pure Mysore silkworm Bombyx mori L. in the preparation of cross breed

Rajendra Mundkur, Mallesha Murthy, K N Nagabhushana Gupta and S Krishna Rao
Karnataka State Sericulture Research and Development Institute,
Thalaghattapura, Bangalore 560 062. India

Received 21st Jan. 2007; Revised 05th March, 2007

Abstract: Sex-limited races can be highly useful tools in the preparation of hybrid combinations. SL-KSPM is a sex-limited polyvoltine race similar to Pure Mysore. The qualitative, quantitative traits and rearing performance are on par with those of Pure Mysore. The grainage performance at commercial level, was studied to compare with Pure Mysore in commercial grainage, of Karnataka. During a year, a total of 1, 62,151 SL-KSPM cocoons (only females) were processed in 15 lots (batches), and 72.430 layings of SL-KSPM x NB4D2 were obtained (42.81 ± 6.15 %). Whereas, in parallel 15 lots, 1,04. 117 Pure Mysore cocoons (both males and females) were processed and 22.424 layings of Pure Mysore x NB4D2 were obtained (21.98 ± 5.01 %). Statistical analysis indicates that the laying yield obtained for SL-KSPM is not significantly different from the expected yield (i.e., the double of that of Pure Mysore, being only females in the sex-limited race). Therefore, the sex-limited polyvoltine race, SL-KSPM can effectively be used in place of Pure Mysore in commercial grainages.