夏秋用家蚕品种9·芙×7·湘和洞·庭×碧·波在推广繁育中的主要经济性状变化

Main Economic Character Variations in Extension and Reproduction of Silkworm Varieties 9·Fu×7·Xiang and Dong·Ting×Bi·Bo for Summer and Autumn Rearing

夏秋用家蚕品种9·芙×7·湘、洞·庭×碧·波在我国蚕茧生产上大面积饲养已有10多年。近期调查2对品种的主要经济性状表明,与品种审定时相比,9.芙×7.湘的全茧量、茧层量、万蚕产茧量、万蚕茧层量、一粒茧丝量、茧丝长和茧丝纤度以及洞·庭×碧·波的全茧量、茧丝长、茧丝纤度等主要经济性状退化达到极显著水平,其中同一品种来自不同繁育地的样本间,其性状成绩差异较大,9·芙×7·湘的万蚕茧层量、解舒率、茧丝纤度以及洞·庭×碧·波的全茧量、茧层量、万蚕产茧量、万蚕茧层量、一粒茧丝量、茧丝长、解舒丝长等性状的变异系数均超过10%。两对品种相比较,洞·庭×碧·波经过10年的繁育,除茧丝洁净外,其它各项经济性状仍优于9·芙×7·湘。建议各地原种繁育单位通过品种亲本(原种)的异地品系杂交或异地繁育继代的方法,取长补短,维持品种的优良经济性状。此外,9·芙×7·湘的原种繁育还应在选留茧丝品质优良蛾区的基础上,注重对产卵性状和饲养性状的选择。

Silkworm varieties 9-Fu ×7.Xiang and Dong.Ting x Bi. Bo have been reared in summer and autumn seasons for cocoon production in China since ten years ago. A recent survey on main economic characters of these two pairs of variety has revealed that, compared to data from variety evaluation, cocoon weight, cocoon shell weight, cocoon weight per 10 000 larvae, cocoon shell weight per 10 000 larvae, single cocoon filament weight, cocoon filament length, cocoon filament size of 9. Fu ×7.Xiang and cocoon weight, cocoon filament length, cocoon filament size of Dong-Ting x Bi. Bo and other main economic traits have declined at an extremely significant level. Among them, samples of the same variety collected from different reproduction sites had quite different data. Traits including cocoon shell weight per 10 000 larvae, reelability and cocoon filament size of 9.Fu ×7-Xiang, cocoon weight, cocoon shell weight, cocoon weight per 10 000 larvae, cocoon shell weight per 10 000 larvae, single cocoon filament weight, cocoon filament length, and non-brokenfilament length of DongTing x Bi Bo all had a variation coefficient of over 10%. A comparison between the two varieties indicated that, after ten years of reproduction, the economic traits of Dong-Ting x Bio Bo were still better than those of 9 Fu × 7. Xiang except for the neatness of cocoon filament. It was proposed that parental stock re-production institutions at each site should conduct hybridization using the parental stocks from different sites or raise the parental stocks at different sites, thus to avail advantages and avoid disadvantages of the stocks and to maintain excellent economic traits of the varieties. In addition, parental stock reproduction of 9-Fu ×7.Xiang should focus on selection for favorable egg-laying and larva-growing traits on basis of selecting moth batches with excellent silk quality.