Authors : M.N.Anil Kumar, Jagadisha M.C and Jayaraju.P
Page Nos : 74-82
Description :
The silkworm, Bombyx mori L. has been reared since time immemorial due to its economic importance. The silk bave is made up of two principle proteins namely, fibroin and sericin. The removal of sericin is known as boil-off loss ratio (B.O.R). It is considered as one of the important qualitative trait during development of breeds, race authorization and even manufacture of silk fabrics. An attempt has been made in the present investigation to record cocoon parameters and boil-off loss ratio in multivoltine races viz., Pure Mysore, Hosa Mysore, Nistari, MU303 and MU1, bivoltine breeds viz., NB4, CSR4, JROP, JRMD and P31. The hybrids (multi bihybrids) of Pure Mysore x NB7, Hosa Mysore x CSR4, Nistari x JROP, MU303 x JRMD and MU1 x P31 were also recorded. The results of the study revealed that, the multivoltine breed MU303 and bivoltine breed CSR2 excelled over other breeds for cocoon weight, shell weight, shell ratio, filament length and denier. Further, significantly lower boil-off loss was registred in MU1, NB7 and Nistari x JROP. All the hybrids expressed better heterosis over mid parental value (MPV) for boil-off loss ratio. Whereas, MU1 x P31 performed well for this trait over better parental value (BPV).
