Effect of protection and refrigeration time outside storeroom on hatching rate of acid-treated diapause silkworm (Bombyx mori) eggs

YU Wu-chang, LI Shu-ming, JIANG Man-gui, LI Guo-dong (Guangxi Academy of Sericulture Sciences/Guangxi Sericulture Technology Extension Station, Nanning 530007, China)

acid-treated silkworm eggs; protection time outside storeroom; refrigeration time; hatching rate; hatching uniformity

[Objective]The present experiment was carried out to investigate the effects of different protection and refrigeration time outside storeroom on hatching rate of acid-treated diapause silkworm eggs in order to provide references for better protecting and storing acid-treated silkworm eggs in future. [Method]The hatching rate and uniformity of acid-trea- ted diapause eggs, obtained from the cross and reciprocal cross F1 hybrids of silkworm variety Liangguang 2,were investigated after protecting them outside the storeroom at 25℃ for 5-60 days and refrigerating at 3-5℃ for 100-175 days. [Result]After protected for 10-60 days and refrigerated for 100-175 days, the practical hatching rate of silkworm eggs was 90.33-97.33%, which met the demand of silkworm eggs quality standard (above 90.00%). Hatching of silkworm eggs was not finished on the same day after refrigerated for 100-175 days and protected for 5-60 days. Silkworm eggs protected for 5-10 d hatched earlier and more uniform than that protected for longer time (15-60 days), that is, the longer the eggs protected, the more difference in their hatching time. [Conclusion]Therefore, protection time outside storeroom did not affect practical hatching rate but affected the uniformity of hatching rate, which was more obvious for the eggs protected within10 days.