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期 刊 ：植物保护学报 2008年

关键词：辣椒疫霉；菌株；交配型分布；致病力差异；

Keywords:Phytophthora capsici, strain, mating type distribution, pathogenicity difference,

摘 要 ：采用单孢菌落直接配对法和游动孢子悬浮液土壤接种法对2003—2006年采自甘肃省辣椒主产区的辣椒疫霉菌菌株Phytophthora capsici进行交配型和致病力测定。结果表明,甘肃省辣椒疫霉菌存在A₁、A₂和A₀三种交配型,以A₁和A₀占优势,在各产区均有分布,发生频率分别达57.9%和31.6%;A₂交配型仅2株,分别出现在酒泉和庆阳。不同来源菌株对5个辣椒品种的致病力存在显著差异,平均病情指数为2.2~56.4,强、中、弱致病性菌株分别占10.6%、52.6%和36.8%,不同地区的菌株致病力有强弱之分,以中、弱致病性菌株为主,同一地区中不同菌株的致病力也存在一定的差异性。

Abstract:In order to know about the mating types and pathogenicity difference of Phytophthora capsici, we conducted the strains of P.capsici occurred in the main regions of planting pepper in Gansu Province from 2003 to 2006. The results showed that there existed in 3 mating types. A₁ and A₀ mating type were the predominant in all strains of P.capsici and distributed in all of sampling regions with frequency 57.9% and 31.6%, respectively. Only two strains of A₂ mating type were found in Jiuquan and Qingyang. The pathogenicity of different strains was tested by using 5 pepper cultivars with soil-inoculation method. The results showed that the great difference was found in pathogenicity and the disease index ranged from 2.2 to 56.4. The high pathogenicity ratio was 10.6%, the medium and low were 52.6% and 36.8%, respectively. The strains that existed in different regions showed different pathogenicity and most of them showed the medium and low pathogenicity, while the pathogenicity of strains isolated from the same region also showed difference.

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