G. it. Ent., 6 (35): 449-453
December 31, 1993
Hybrid vigour in the silkworm, Bombyx mori (L.)
by
S. K. BHARGAVA, V. THIAGARAJAN, R. K. DATTA
Abstract - The hybrid vigour of 20 F1 hybrids raised from 5 silkworm parental races (N4, 14M, SPJ1, JC2P and SH2) was calculated in terms of mid parent heterosis, better parent heterosis and check heterosis. The observations were made on 6 economically important characters, namely, larval duration, cocoon yield (number and weight), single cocoon weight, single shell weight and shell ratio. Two hybrids, namely, N4 x JC2P (except for the larval duration) and N4 x SH2 (except for the shell ratio) showed best values of better parent heterosis for all the characters. Through the least significant difference value (P = 0.05), only two hybrids, namely, SPJ1 x N4 and N4 x SH2 showed maximum check heterosis (17.18 and 15.76 respectively) for the cocoon yield (weight). The results indicate that the hybrid vigour noticed in the silkworm (Bombyx mori) is very useful to improve the existing races for commercial purpose, and to develop new races through the hybridization technique.
