甘薯抗薯瘟病的遗传及其与产量性状的关系

用９个不同抗瘟型的甘薯品种做亲本，对其杂交后代分菌系接种鉴定，并考察部分组合后代的产量性状．结果表明，甘薯对薯瘟Ⅰ型菌系抗性由显性主效基因控制，母本细胞质效应小．对Ⅱ型菌系抗性则呈现广泛的分离，并有超亲现象；双亲为抗病的组合，其后代出现抗病型的频率比抗×感或感×感的组合有明显提高，显示出加性效应的遗传特点．相关分析可看出，甘薯Ｆ１抗Ⅱ型菌系的能力与鲜薯重呈负相关，与干率呈弱相关．

Inheritance of bacterial wilt resistance and its correlation with yield traits in sweetpotato

Crosses and reciprocal crosses among 9 cultivars with different resistance were conducted and resistance of F 1 progenies against 2 athogenic bacterial pathotype (Ⅰ or Ⅱ) of Ralstonia solanacearum was investigated by inoculation under field conditions. The results showed that inheritance of resistance to bacterial wilt (pathotype Ⅰ) was controlled by major dominant gene, exhibiting qualitative traits, and effect of female parent was low. Meanwhile, the range of distribution of resistance to bacterial wilt (pathotype Ⅱ) in F 1 progenies was wide, and individuals with resistance exceeding parents could be selected and inheritance of bacterial wilt resistance was controlled by multigene. In addition, correlations between F 1 seedling resistance to bacterial wilt (pathotype Ⅱ) and fresh root weight, and between dry matter content and the ratio of tuber/plant were analysed and it was found that there was a significant positive correlation(r 1=0.647 ** , r 2=0.526 *) between fresh root weight and wilt index in F 1 progenies from the combination involving parents of higher susceptible, but insignificant correlation between dry matter content and resistance to bacterial wilt (pathotype Ⅱ).