author(s)
Bharath Kumar Neelaboina, Shivkumar, Mir Nisar Ahmad and MK Ghosh

abstract
The present study was undertaken to evaluate the performance of eleven bivoltine silkworm, Bombyx mori L, breeds (CSR2, CSR6, CSR27, CSR26, CSR50, PAM114, PAM117, APS4, APS5, SK6 and SK7) of different origin under temperate climatic conditions during spring, summer and autumn, 2018 at Central Sericultural Research and Training Institute, Pampore, Jammu and Kashmir. The rearing was carried out under uniformed laboratory condition by adopting the standard method. These eleven breeds were evaluated for their performance in eight metric traits viz., fecundity (No.), hatching (%), yield per 10,000 larvae by number and by weight (kg), single cocoon weight (g), single shell weight (g), shell ratio (%) and pupation rate (%). The performance of breeds varied from season to season since they originated from different progenitors. The data generated was analyzed statistically and subjected to multiple trait Evaluation index (E.I). On the basis of the evaluation index values ranking CSR2, CSR26, CSR27, CSR50, PAM114 and PAM117 performed well in all the three seasons with E.I values above 50. Two breeds APS5 and CSR6 recorded E.I values below 50 in all the three seasons. APS4 has performed well in only spring season whereas SK6 and SK7 recorded E.I values above 50 in summer and autumn only. Based on their performance in all the three seasons, these parental breeds will be utilized for development of foundation crosses which will be further shortlisted for the development of bivoltine silkworm double hybrids suitable to temperate region of J&K as an alternate for ruling CSR double hybrid.