云南番茄致病疫霉的交配型、甲霜灵敏感性及毒力类型

Characteristics of mating type,metalaxyl sensitivity and virulence of Phytophthora infestans on tomato in Yunnan,China

对2003～2004年云南省番茄致病疫霉的交配型、甲霜灵敏感型、毒性因子及毒力类型进行了系统的测定和分析.结果表明：云南番茄致病疫霉只存在A1交配型,未发现A2交配型或自育型.甲霜灵抗性和中抗菌株是主要菌系,抗性、中抗、敏感菌株分别占测定菌株的51.2%、31.7%、17.1%.云南番茄致病疫霉居群对已知的抗性基因R1、R2、R3、R4、R6、R7、R8、R9、R10、R11有毒性,其毒性频率在9.8%～95.1%之间.测定的61个菌株中检测到26种不同的毒力类型,每种类型平均含有5.2个毒性因子,其中毒力类型1.3.4.7.9出现频率最高,为优势的毒力类型,出现频率为44.3%,其次为1.3.4.6.7.9、1.3.7.9,出现频率均为4.9%,其它23种毒力类型出现频率仅在1.6%～3.3%之间.云南番茄致病疫霉居群显示了复杂的表型特征.

The characteristics of mating type, metalaxyl sensitivity and virulence of Phytophthora infestans isolates collected from tomato in Yurman during 2003 to 2004 were analyzed systematically. The results showed that A2 or self-fertility isolate was absent, and only AI mating type was detected from P infestans population on tomato. Resistant and moderately resistant isolates to metalaxyl were common lineages on tomato in Yurman and the ratio of resistant, moderately resistant and sensitive isolates was 51.2%, 31.7% and 17.1% respectively. Among sixty-one isolates virulent to known resistance gene R1, R2, R3, R4, R6, R7, R8, R9, RIO and Rll with the frequency from 9.8-95.1%, a total of twenty-six different virulence patterns was detected and each virulence contained 0-9 virulence factors with mean of 5.2. The main virulence patterns were 1.3.4.7, 1.3.4.6.7.9 and 1.3.7.9. The virulence 1.3.4.7 was predominant among the populations and the others showed low frequency ranged from 1.6 to 4.9%. The result indicated that the characteristics of P. infestans populations on tomato in Yurman were diverse and complicated.