天蚕与美洲野蚕远缘杂交后代的生殖力及染色体观察

以天蚕为母本 ,以美洲野蚕为父本的远缘杂交后代的生殖力观察表明 ,无论是同蛾区交配、异蛾区交配 ,还是回交天蚕及美洲野蚕 ,其后代都具有生殖能力 ,已饲养至F7代。这种正常生殖力的细胞遗传学基础是二者在染色体水平上具有明显的同源性 ,其后代的单倍染色体数似双亲 ,多为 30、31,分别占 5 3%和 38 2 %。

Investigation on the Fertility and Chromosome of Distant Crossing Hybrid of A.yamamai and A.polyphemus

On the fertility of the filial generation of distant crossing hybrid in which the A.yamamai was as its female parent and A.polyphemus as male parent,the progenies are all fertilizable and have been reared up to 7th generation.No matter what kind of crossing form such as,interbatch crossing,intrabatch crossing or backcrossing with A.yamamai or A.polyphemus, the cytogenetics basis of this kind of normal fertility is that A.yamamai and A.polyphemus are of chromosome homology,the number of the monoploid chromosome of their filial generations are mostly 30 or 31,the percentage is 53% and 38.2% respectively.