家蚕品种云蚕8的斑纹限性定向转育

Larval Stripe Sex-limited Directional Introduction and Selection in Silkworm Variety Yuncan 8

针对云南省现行普通家蚕品种云蚕8制种过程需鉴别雌雄蛹的问题,以保存的强健性斑纹限性家蚕基础品种H05和2032分别与云蚕8A及云蚕8B杂交,采用回交并结合标志基因选择的方法进行斑纹限性定向转育,获得了新的斑纹限性品种云蚕8A限和云蚕8B限。新品种的经济性状与原品种相仿,组配的杂交组合云蚕7×云蚕8限的健康性优于原品种的杂交组合云蚕7×云蚕8,且茧丝长、解舒率和干茧出丝率分别提高了8.75%、5.44%、0.94%。定向转育的家蚕斑纹限性品种不仅具有可在幼虫期通过斑纹鉴别雌雄的特点,而且主要经济性状成绩接近或超过原品种,特别是强健性有所提高,将在降低蚕种生产成本以及实现雌雄茧分别缫丝等方面发挥作用。

Aiming at solving the problem of distinguishing male and female pupae during eggs production for current silk- worm variety Yuncan 8 in Yunnan Province, two preserved larval stripe sex-limited silkworm （ Bombyx mori） basic variety with strong vitality, namely H05 and 2032, were selected for hybridizing with silkworm varieties Yuncan 8A and Yuncan 8B respectively. Back-crossing was conducted in combination with selection via marker genes for directional introduction and selection of the larval stripe sex-limited trait. As a result, two new larval stripe sex-limited silkworm varieties Yuncan 8A xian and Yuncan 8B xian were obtained. Economic traits of the new varieties were close to those of the original varie- ties. Meanwhile, healthiness of the prepared Yuncan 7 xYuncan 8 xian hybrid combination was better than that of the original variety Yuncan 7 xYuncan 8, and cocoon filament length, reelability and silk rate of dry cocoons were 8. 75%, 5.44% and 0.94% higher as well. Female and male larvae of the new varieties could be distinguished by examining the stripes on their bodies. Nevertheless, their main economic traits were better or close to the original varieties. Especially,healthiness of the new varieties was improved considera- bly. The new varieties will play an important role in reducing the cost of eggs production and reeling male and female cocoons separately.