关于水稻的一篇文章节.docVIP

利用单基因鉴别体系鉴定云南稻瘟病菌生理小种 摘要 稻瘟病是全世界最具毁灭性的病害之一，严重威胁着世界水稻产量的稳定。种植抗性品种是防治稻瘟病最经济、有效的方法，新毒性小种的产生会导致水稻抗病性丧失，分析田间稻瘟病菌群体结构的组成及变异对农作物抗性基因的合理利用具有重要价值。本研究利用国际水稻研究所（IRRI）以中国普感品种丽江新团黑谷为回交亲本选育的水稻近等基因品系（IRBL鉴别品系），对云南省楚雄、大理、芒市3个稻作区采集、分离的50个稻瘟病菌单孢菌株的生理小种进行了鉴定。结果表明，供试的50个稻瘟病菌株被划分48个稻瘟病菌生理小种,其中出现频率最高的为U73-i7-k007-z00-ta403小种，检测出3次，其余小种均只检测出一次。云南稻瘟病菌对水稻单基因系IRBLkh-K3(Pik-h)、IRBL9-W（Pi9）、IRBLz-Fu（Piz）、IRBL1-CL（Pi1）、IRBLkm-Ts（Pik-m）、IRBLz5-CA-1（Piz-5）、IRBLks-S（Pik-s）、IRBLta-K1（Pita）及持有Pita-2的IRBLta2-Pi和IRBLta2-Re的毒力频率低于20%，表明这些抗性基因对云南稻瘟病菌具有广谱抗性。 关键词：稻瘟病菌；生理小种；单基因鉴别品种；毒力频率 Identification system using single gene identified races of Pyricularia grisea Abstract Magnaporthe oryzae causes the plant disease known as rice blast and is one of most devastating diseases of rice worldwide. Breeding for resistance is the most economical way within the integrated disease management strategy. However, the appearance of new virulent races and their build up makes it possible for the breakdown of resistance of such new cultivars. The rice blast fungus Magnaporthe oryzae is known to be highly variable. Thereofre, genetic diversity in the Magnaporthe oryzae population was studied to facilitate the rice breeding for durable resistance and the disease integrated management.A total of 50 blast monoconidial isolates collected from 3 prefectures of Yunnan Province were tested using monogenic lines which hold 23 different resistance genes. These monoconidial isolates were divided into 48 races based on the reactions to IRBL lines, the dominant race was U73-i7-k007-z00-ta403,which detected in three isolates, the remained races were detected only in one isolate, respectively. The nine blast resistance genes Pi9, Piz, Pi1, Pik-s, Piz-5,Pik-m, Pita, Pita-2and Pik-h were found to confer resistance to a wide spectrum of resistance. These resistance genes and monogenic lines should be useful for breeding for improved resistance in Yunnan province. Key words: Magnaporthe oryzae;monogenic lines;pathogenicity a