一年继代1次的蚕种单式库外保护和单式冷藏试验

Single Storage Protection and Single Cold Storage Test of Silkworm Seed once a Year

以广西蚕区大面积饲养的二化性含多化性血统的家蚕品种两广二号一代杂交种供试,探索二化性和二化性含多化性血统的家蚕种质资源一年继代1次的蚕种保护和冷藏方法。试验首先将供试蚕种的保护分2个阶段,第1阶段将蚕种库外保护期(25℃)+库内冷藏期(3.5℃)的时间设置为320 d,第2阶段将蚕种从出库催青至化蛾产卵的时间设置为45 d,并将第1阶段又细分为9种处理:库外越夏保护时间分别为10 d、40 d、70 d、100 d、130 d、160 d、190 d、220 d、250 d,库内冷藏时间分别对应为310 d、280 d、250 d、220 d、190 d、160 d、130 d、100 d、70 d。试验结果:两广二号正交种库外越夏保护40~190 d再入库冷藏的平均孵化率均≥92%,库外越夏保护时间分别为10 d、220 d、250 d再入库冷藏的平均孵化率分别为43.20%、84.22%、65.11%;两广二号反交种库外越夏保护70~250 d再入库冷藏的平均孵化率均≥90%,均达到部颁桑蚕一代杂交种越年种孵化率≥90%的标准,而库外越夏保护时间10 d或40 d再入库冷藏的平均孵化率则只有2.52%和68.09%。以上试验结果初步提示:二化性和二化性含多化性血统的家蚕品种资源一年继代1次保种,其产卵后越夏保护时间应以不少于70 d但又不超过190 d为宜,冷藏时间以130~250 d为宜,且库外越夏保护时间与库内冷藏时间之和应该控制在320 d左右。

In this paper,the methods of protecting and refrigerating the silkworm germplasm resources of Bombyx mori(Bombyx mori)with binary and binary polyclonal lineages were studied by using the hybrid strains Liangguang No.2,which were reared in large areas in silkworm region of Guangxi.In the first stage,the incubation period(25℃)followed by storage period(3.5℃)was set at 320 d.In the second stage,the incubation period from storage to oviposition was set at 45 d.The first stage was divided into 9 treatments:The oversummer protection time was 10 d,40 d,70 d,100 d,130 d,160 d,190 d,220 d and 250 d,respectively.The refrigerating time in the storage is 310 d,280 d,250 d,220 d,190 d,160 d,130 d,100 d and 70 d respectively.The results were as follows:the average hatching rates of Liangguang No.2 orthogonal species were all≥92%after 40 d to 190 d of summer storage,and the average hatching rates were 43.20%,84.22%and 65.11%after 10 d,220 d and 250 d of summer storage,respectively.The average hatching rates of Liangguang No.2 reverse cross species were all≥90%after 70 d to 250 d of oversummer storage,which reached the standard of≥90%for the first generation of silkworm hybrids.However,the average hatching rates of Liangguang No.2 reverse cross species were only 2.52%and 68.09%after 10 d and 40 d of oversummer storage.Preliminary test results demonstrated that for bivoltine and bivoltine with polyvoltine genetic background silkworm variety resources that subculture once a year,the oversummer protection time after the oviposition should be not less than 70 d but not more than 190 d optimally,and at the same time,the cold storage time should be 130~250 d optimally.Furthermore,the sum of the oversummer protection time outside the storehouse and the refrigeration time inside the storehouse should be controlled at about 320 days.