家蚕二元种和四元种五龄中、后期青蚕绝食上簇对茧质的影响

Influence On Cocoon Quality by Hunger-cocooning of the Unmatured Larvae of F_1 Hybrid and Double Hybrid in Silkworm

本研究表明，无论二元种还是四元种，五龄食桑９６小时的青蚕，就可结小型茧。随食桑时间延长，其全茧量和茧层量迅速增加，茧层率呈直线上升。四元种个体间茧质开差大于二元种。食桑６足天（１４４小时）到７足天（１６８小时），二元种的茧层率增长减缓，而四元种仍不减慢。到食桑７足天后的四元种个体间茧质开差缩小到同二元种几乎相仿。因此，五龄后期良桑饱食是提高四元种茧质整齐度的重要途径。

During the middle or late stage of sib instar,the larvae of both F1 hybrid and double hybrid were able to cocoon fed on mulberry in 96 hours. with the duration of feeding,their cocoon weight and cocoon shell weight increased rapidly,their cocoon shell percentage increased also very fast and the individual cocoon quality showed more differences among the double hybrids than among the F1 hybrids. The increase of cocoon shell percentage of the F1 hybrids fed on mulberry in 6 days was slower than that of the double hybrids. The difference of individual cocoon quality decreased significantly among the double hybrids only after 7 days on mulberry. So it is very important path to be given enough mulberry of good quality to raise the degree of unanimity of cocoon quality in the double hybrids of silkworm.