家蚕品种茧丝强伸力差异分析及育种素材评价应用

Difference analysis of strength and elongation among cocoon filaments of silkworm races and application evaluation of breeding material

【目的】了解不同家蚕品种间的茧丝强伸力差异性,为家蚕育种素材选择提供参考依据。【方法】从48个家蚕品种中各取两粒茧幅一致的蚕茧,对不同百回的茧丝进行强伸力与纤度检测,用SPSS 17.0软件对茧丝的断裂强力、断裂伸长、强度等测试项目进行方差分析,比较不同品种间相同茧丝部位、不同茧层部位及茧丝强伸度较优部位的断裂伸长差异性,对育种素材进行评价。【结果】48个家蚕品种中,茧丝断裂伸长最高2.73 mm,最低1.76 mm;断裂强力最高18.3 CN,最低10.5 CN;强度最高5.46 CN/dtex,最低3.13 CN/dtex。不同品种的茧丝断裂强力、断裂伸长差异较大,且同一品种内不同茧层的断裂强力、断裂伸长也存在明显差异。茧丝强伸力较优的部位处于第3~6百回间,对48个家蚕品种第3~6百回茧丝断裂伸长进行方差分析,结果发现编号为2、5、1、6、12、9、3、4、18、21的品种与其他品种存在显著差异（P〈0.05）,伸度较优（断裂伸长率在26%以上）。【结论】茧丝强伸力较优的部位处于茧层第3~6百回,在家蚕育种素材评价时应结合亲本选择过程中活蛹缫丝同时进行,才能使茧丝性状间综合性应用得到提高,最终培育出强伸力较优的家蚕品种。

[Objective ]Strength and elongation variation among different silkworm （Bombyx mori） varieties were studied to provide references for screening breeding materials of silkworm. [Method]Two grains with identical cocoon width of 48 varieties of silkworm cocoon were selected. Strength and elongation of per hundred HUI at the same place in cocoon filament were tested. Using SPSS 17.0 software, breaking strength, breaking elongation and the intensity of cocoon filament were compared among cocoon filament of different varieties of silkworm and a cocoon filament with better elongation was confirmed in the same breed. Lastly, breeding materials were evaluated. [Result]Among 48 silkworm races, the least and the largest breaking force was 10.5 and 18.3 CN, respectively. The breaking elongation size ranged from 1.76 to 2.73 mm. The least strength and largest strength was 3.13 and 5.46 CN/dtex, respectively. Breaking strength, breaking elongation and intensity varied in different cocoon layers in the same species. The range of 300-600 revolutions displayed better strength and elongation. Variance analysis on breaking elongation of 300-600 revolutions of 48 varieties showed that 2, 5, 1, 6, 12, 9, 3,4,18 and 21 had better elongation with elongation rate of over 26% and they were significantly different from other varieties （P〈0.05）. [Conclusion]300-600 revolutions of 48 varieties have better strength and elongation. Living pupa and reeling silk should be synthetically considered in evaluating breeding materials, through which silk can be utilized more widely and better silkworm cultivars can be bred.