【摘要】 利用已知的43个Sr单基因系对我国小麦秆锈菌群体中的8个生理小种的致病谱进行了测定，并结合1991～1997年我国小麦秆锈菌各生理小种在自然界的出现频率，分析了毒力基因数目多少与小种竞争能力的关系。结果表明：毒力基因数目存在一个最适范围，毒力基因的过度缺失或增加都会给小种的相对竞争能力造成损失。更多还原

【Abstract】 According to gene-for-gene theory, the pathogenetic spectrum of the races of wheat stem rust in China was toted with the known single Sr genes of wheat. There was much difference among those races. The result was used to analysis the competitive ability. There minght be a suitable range of the number of virulent genes in stem rust races for competitive ability.更多还原