Institute of Microbiology of the ASCR, v.v.i, Vídeňská 1083, 142 20 Praha 4, Czech Republic.
Mycologia. 2011 Mar-Apr;103(2):325-32. doi: 10.3852/10-124. Epub 2010 Oct 1.
Widespread morbidity and mortality of Juglans nigra has occurred in the western USA over the past decade. Tree mortality is the result of aggressive feeding by the walnut twig beetle (Pityophthorus juglandis) and subsequent canker development around beetle galleries caused by a filamentous ascomycete in genus Geosmithia (Ascomycota: Hypocreales). Thirty-seven Geosmithia strains collected from J. californica, J. hindsii, J. major and J. nigra in seven USA states (AZ, CA, CO, ID, OR, UT, WA) were compared with morphological and molecular methods (ITS rDNA sequences). Strains had common characteristics including yellowish conidia en masse, growth at 37 C and absence of growth on Czapek-Dox agar and belonged to a single species described here as G. morbida. Whereas Geosmithia are common saprobes associated with bark beetles attacking hardwoods and conifers worldwide, G. morbida is the first species documented as a plant pathogen.
在过去的十年中，美国西部广泛发生了黑胡桃的发病率和死亡率。树木死亡是由胡桃枝天牛（Pityophthorus juglandis）的侵袭性进食以及随后由丝状子囊菌属（Geosmithia）（子囊菌门：Hypocreales）中的一种真菌在甲虫坑道周围引起的溃疡发展所致。从美国七个州（亚利桑那州、加利福尼亚州、科罗拉多州、爱达荷州、俄勒冈州、犹他州和华盛顿州）的加州黑胡桃、黑胡桃、黑胡桃和黑胡桃中收集了 37 株 Geosmithia 菌株，并通过形态学和分子方法（ITS rDNA 序列）进行了比较。这些菌株具有共同的特征，包括大量的黄色分生孢子、在 37°C 下生长以及在察氏琼脂上不生长，属于一种在这里被描述为 G. morbida 的单一物种。尽管 Geosmithia 是与攻击硬木和针叶树的树皮甲虫相关的常见腐生菌，但 G. morbida 是第一个被记录为植物病原体的物种。
