杨丽娜　段国华　覃雁瑜　祝雯　潘哲超　隋启君　詹家绥

摘 要 利用11个含有不同单显性（R1、R2、R3、R4、R5、R6、R7、R8、R9、R10、R11）抗马铃薯晚疫病的鉴别寄主，对云南省会泽县村同一发病田块前、中、后期3个群体的马铃薯晚疫病菌59、158和75个菌株进行毒性频率和小种鉴定，分别鉴定出31、60和30个小种，大部分小种只检测到一次，其中优势小种为超级小种（含有11个毒性基因的晚疫病菌），占整个群体的53.33%；随着发病时间的推移，优势小种频率、小种复杂度呈上升趋势，但小种多样性呈降低趋势，在马铃薯生育期间除了avr4外，其它毒性基因的频率未发生显著变化。实验结果表明云南省马铃薯晚疫病菌小种演化速度快，小种结构复杂，在该地区种植起源于Solanum demission的R1～R11抗性基因存在较高的失效风险。

关键词 马铃薯晚疫病菌；毒性基因；小种；进化；鉴别品种；病害防治

中图分类号 S435.32 文献标识码 A

Abstract Race and virulence factor of 59， 158 and 75 Phytophthora infestans isolates sampled from early， middle and late stages of late blight epidemics respectively in a potato field located in Huize，Yunnan in 2012 evaluated on 11 potato differentials each carrying one of R1-R11 resistance genes. A total of 31， 60 and 31 races were found in the early-， middle-and late-epidemic season， respectively. Super-race able to induce the late blight disease on all 11 differentials dominated in all three collections， accounting for 53.33% of combined population， while most of other races were detected only once. Over the potato growing season， the frequency of the super-race and race complexity gradually increased while the race diversity decreased directionaly. Except avr4， no significant change in the frequency of virulence factors was detected over the single growing season. These results suggest a quick evolution of race structure and an increasing risk of major resistance breakdown in Yunnan.

Key words Phytophthora infestans；Virulence factor；Race complexity；Evolution；Differential cultivar；Disease management

doi 10.3969/j.issn.1000-2561.2016.01.026

随着种植面积的不断扩大，马铃薯已经成为仅次于水稻、小麦和玉米的第四大粮食作物[1]，因此其病害防治工作也越来越受到人们的重视。由致病疫霉Phytophthora infestans（Mont.）de Bary引起的晚疫病是马铃薯的最主要病害，据文献记载该病害曾导致爱尔兰大饥荒，造成数百万人口死亡和流离失所，影响着世界人口分布[2]。目前，晚疫病仍然是马铃薯的毁灭性病害[3]，每年全球由该病害引起的直接经济损失高达上百亿美元[4-5]。

喷施化学农药和种植抗性品种是防治马铃薯晚疫病的主要措施。喷施化学农药虽然可以在短期内获得良好的防治效果，但存在使用成本高、污染环境及农药残留等问题。……