Phytophthora inundata sp nov., a part heterothallic pathogen of trees and shrubs in wet or flooded soils
Phytophthora inundata sp nov., a part heterothallic pathogen of trees and shrubs in wet or flooded soils
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DOI：
10.1017/s0953756203007548
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发表时间：
2003-04-01
影响因子：
--
通讯作者：
Kirk, SA
中科院分区：
文献类型：
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作者：
Brasier, CM;Sanchez-Hernandez, E;Kirk, SA
树木和灌木的疫霉属病原体，以前称为疫霉属 sp。 O-group 正式命名为 P. inundata sp。十一月P. inundata 属于 P. gonapodyides-P。 megasperma Major ITS Clade 6，其目前已知的最近亲是 P. humicola。其孢子囊无乳头状，卵原体较大（平均约40μm），卵孢子壁厚，两性花药，菌落类型独特，最适生长温度高，为28-30℃，最适生长速度快，生长上限高，为35-37℃。对 8 个 P. inundata 分离株的育种系统的研究表明，它们是典型的异宗合体，具有 A1 和 A2 亲和类型。然而，一些 P. inundata A1 x A2 组合未能交配，即使相同的分离株与 P. drechsleri 测试者成功交配。其他的则是“沉默”的 A1 或 A2，无法产生自己的配子体，但能够在另一个物种的异性相容性类型中诱导配子体形成。这表明该物种的性机制部分崩溃。两个分离株（一个 A1 和一个 A2）出人意料地嵌合自花受精，表明 A1 + A2 染色体异倍体。讨论了 P. inundata 与池塘和河流以及洪水后树木和灌木的根腐病和颈腐病的关系。
A Phytophthora pathogen of trees and shrubs previously designated Phytophthora sp. O-group is formally named as P. inundata sp. nov. P. inundata falls within the P. gonapodyides-P. megasperma major ITS Clade 6, its present nearest known relative being P. humicola. It has non-papillate sporangia, fairly large oogonia (average ca 40 mum) with thick walled oospores, amphigynous antheridia, a distinctive colony type, a high optimum temperature for growth of 28-30 degreesC, fast growth at the optimum, and a high upper temperature limit for growth of ea 35-37 degrees. A study of the breeding system of eight P. inundata isolates showed them to be classically heterothallic with A1 and A2 compatibility types. However some P. inundata A1 x A2 combinations failed to mate even though the same isolates mated successfully with P. drechsleri testers. Others were 'silent' A1s or A2s, unable to produce their own gametangia but able to induce gametangial formation in the opposite sexual compatibility type of another species. This indicates a partial breakdown of the sexual mechanism in the species. Two isolates (one A1 and one A2) were unpredictably and chimaerically self-fertile, suggesting A1 + A2 chromosomal heteroploidy. The association of P. inundata with ponds and rivers and with root and collar rots of trees and shrubs after flooding is discussed.