半脱皮对家蚕生长与生产繁殖性能的影响

Effect of Semi-exuviation on Growth,Production and Reproduction Performance of Bombyx mori

【目的】探明家蚕半脱皮行为发生及其对家蚕生长和生产繁殖性能的影响,为家蚕新品种的选育及扩大蚕桑生产提供理论依据。【方法】以四川省农业科学院蚕业研究所保育的X-1(A_(1))、X-2(A_(2))、X-3(A_(3))和锦12(A_(4))共4个家蚕品种为研究对象,采用双因素试验研究其在常规饲育(T_(1),CK)、眠中干燥(T_(2))和人工去除蜕皮着点(T_(3))条件下正常蚕与半脱皮蚕的生长和生产性能。【结果】各品种T_(1)、T_(2)和T_(3)半脱皮蚕的发生率分别为1.0%~2.5%、8.0%~23.5%和9.5%~42.5%,品种间和同一品种不同处理间差异分别达显著水平和极显著水平。半脱皮蚕通过人工剥离虽然能正常吐丝结茧羽化产卵,但其龄期经过(全龄经过和5龄经过)较正常蚕略长(0.29~0.71 d和0.33~0.67 d),4龄健蛹率较正常蚕低7.25%~7.99%;正常蚕和半脱皮蚕营制的蚕茧对茧层率影响较小,其茧层率与品种本身的遗传有关,但半脱皮蚕茧的全茧量和茧层量低于正常蚕茧,分别低5.49%~8.33%和7.21%~14.16%,直接影响蚕茧的产量;半脱皮蚕通过人工剥离虽然能够正常羽化产卵,产卵量和不良卵量平均分别为222粒和18粒,较正常蚕(483粒和4粒)分别显著降低(54%)和显著升高(350%),直接影响品种的繁育性能。【结论】家蚕眠中干燥或去除脱皮着点不利于家蚕脱皮,容易产生半脱皮蚕或不脱皮蚕;半脱皮蚕直接影响蚕茧的产量和品种的繁育性能。

【Objective】The effect of semi-exuviation on growth,production and reproductive performance of Bombyx mori is explored,which provides theoretical basic for breeding new variety and expanding sericultural production.【Method】Four B.mori varieties bred in Sericultural Research Institute,Sichuan Academy of Agricultural Science are used as research objects,and a two-factor experiment is conducted to study the growth and production performance of normal and semi-exuciated B.mori under the conditions of conventional breeding(T_(1),CK),drying treatment at dormancy stage(T_(2))and artificial removal of molting point(T_(3)).【Result】Under T_(1),T_(2) and T_(3) treatment,the incidence rate of semi-exuviated B.mori was 1.0% ~ 2.5%,8.0%~23.5% and 9.5%~42.5%,respectively.The differences of same variety and among varieties under different treatments reached significant level and extremely significant level,respectively.Although incompletely exuviated B.mori could spin cocoons,ecolse and spawn normally by artificial exfoliation,the instars duration(full and fifth instars) were slightly longer than normal B.mori(0.29~0.71 d and 0.33~0.67 d) and the healthy pupa ratio of the fourth instars larvae with semi-peeling was 7.25%~7.99% lower than normal B.mori.Both normal and semi-exuviated B.mori had little effect on cocoon shell rate which was related to the heredity of the variety itself.But the whole cocoon weight and cocoon shell weight of semi-peeled B.mori were 5.49~8.33% and 7.21~14.16% lower than normal B.mori,respectively,which directly affected the yield of cocoons.Although incompletely exuviated B.mori could eclose and spawn normally by artificial exfoliation,the oviposition quantity and the number of poor egg was 222 and 18,respectively,which significantly decreased(54%) and increased(350%) compared with normal B.mori,(483 and 4),respectively,and directly affected the breeding performance of B.mori variety.【Conclusion】Drying treatment at dormancy stage or artificial removal of molting points is bad for the exuviations of B.mori,and would easily result in the semi-exuviated or non-exuviated B.mori.The semi-exuviated B.mori directly affects the cocoon yield and breeding performance of B.mori variety.