USDA-ARS, Root Disease and Biocontrol Laboratory, 365 Johnson Hall, Washington State University, Pullman, Washington 99164-6430.
Mycologia. 2003 Jan-Feb;95(1):80-6.
A new species of Pythium isolated from wheat and apple roots in eastern Washington is described. Pythium abappressorium sp. nov. is characterized by abundant appressoria. Plerotic oospores and sporangia are formed from the appressoria and remnants of the appressoria remain attached to the base of sporangia at maturity. Smaller appressorial swellings, reminiscent of hyphal swellings, are also formed within the appressoria. Pythium abappressorium is pathogenic to wheat, causing damping-off and stunting, but is not pathogenic to apples. The fungus can grow in the temperature range 5 to 30 C, with an optimum of 20 C. The sequence of the ITS1 region of the rDNA did not match the sequences from a worldwide collection of over 1200 isolates, including types and neotypes, suggesting that this species has not been previously described.
从华盛顿东部的小麦和苹果根部分离到的一个新的喇叭菌物种被描述。新种 Pythium abappressorium 的特征是丰富的附着胞。充满营养的卵孢子和孢子囊从附着胞形成，而附着胞的残余物在成熟时附着在孢子囊的基部。在附着胞内还形成较小的附着胞肿胀，类似于菌丝体肿胀。Pythium abappressorium 对小麦致病，引起猝倒和矮化，但对苹果没有致病性。该真菌可在 5 到 30°C 的温度范围内生长，最适温度为 20°C。rDNA 的 ITS1 区域的序列与来自全球超过 1200 个分离物的序列（包括类型和新类型）不匹配，这表明该物种以前没有被描述过。
