摘要： 稻瘟病菌90-2菌株系是从大田水稻雄性不育细胞质（CMS）上分离的对野败型（W）CMS专化致病的生理小种。研究表明，该菌株产生的毒素在致病过程中起着一定作用。本试验测定了此菌株在不同pH培养基中培养对毒素产生的影响、毒素的热稳定性及pH值变化对毒素活性的影响等。离体叶片法测定毒素活性发现毒素使离体叶段褪绿和细胞坏死，珍汕97A褪绿程度大于珍汕97B,进一步测定了毒素对W珍汕97A、97B叶绿素总含量的影响和对W珍汕97A、97B呼吸作用的影响，初步测定了粗毒素的致病作用。用根冠细胞法测定了90-2菌株毒素对一套4种同核异质CMS材料的致病力，表明稻瘟病菌90-2菌株是CMS野败型的专化生理小种。

关键词: 水稻, 稻瘟病菌, 毒素, 雄性不育细胞质

Abstract: Pyricularia oryzae 90 2 strain which is isolated from rice CMS in field is selectively pathogenic to rice W CMS. The strain produces toxin that plays an important role in pathogenic process. This paper reports heat stability of the toxin and effects of pH on toxin production. The experiments show that toxin from 90 2 strain is heat stable and variations of pH value to certain extent affects the activities of toxin. The change of pH value of medium also alters the activities of the toxin. We observed that the toxin lead to the yellowing of leaves and cell necrosis. The degree of yellowing of W Zhenshan 97A leaves is larger than that of Zhenshan 97B. The experiments detected the influence of the toxin on total content of chlorophyll and respiration of W Zhenshan 97A and 97B respectively. In addition, we detected the pathogenicity of the toxin to one set of rice materials with homocaryon using the method of root cap cells bioassay. The experiment confirms that 90 2 strain is special susceptibility to rice with W CMS.

Key words: Rice, Pyricularia oryzae, Toxin, Male sterile cytoplasm

中图分类号: 

• S435.11