Evaluation of survival rate, cocoon, silk yield and quality of stored silkworm pure lines and their hybrids as genetic resources under producers conditions

The research has been carried out to determine the pure lines and hybrids that can be used in production instead of M, N pure lines and M x N hybrid used for production for breeding silkworm eggs, fresh cocoons and raw silk for more than 40 years. The main objective was to determine the performance of ZB, ZF pure lines and their hybrid in producer conditions as an alternative to M, N pure lines and their hybrids. The experiment was carried out with three replicates for each pure line and hybrid. In this study, egg characteristics (fecundity, number of fertilized eggs, hatchability), larvae and pupae characteristics (larvae duration, survival rate, mature larvae weight, silk gland weight, pupation rate), cocoon and silk yield characteristics (cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon amount in kg, cocoon quantity per liter, cocoon length, cocoon width, filament length, filament weight, denier) were determined. The correlations between characters for each line and hybrid and heterosis was determined in related to egg, larva, cocoon and silk characteristics. No significant differences were found in egg characteristics between pure lines and hybrids whereas all traits of larvae and pupae were significant (P<0.01). In addition, ZF x ZB hybrid showed superior performance in terms of silk gland weight (P<0.01). As regards to larvae and cocoon characteristic, ZF x ZB hybrid was showed positive and significant heterosis for cocoon weight, silk gland weight, mature larval weight in comparison to M x N hybrid. Correlation coefficients of egg, larvae, pupae and silk characteristics were calculated for pure lines and hybrids (P<0.01;0.05). Significant positive and negative correlation coefficients were determined in pure lines and hybrids in terms of egg, larvae, cocoon and silk characteristics in ZF x ZB hybrid and pure lines except M x N hybrid.