Phytopathology. 1998 Sep;88(9):922-9. doi: 10.1094/PHYTO.1998.88.9.922.
ABSTRACT Three similar isolates of Phytophthora (Phytophthora sp-h) were obtained from diseased Spathiphyllum and Primula plants. Cultural characteristics did not fit any known description of Phytophthora species. The Phytophthora sp-h isolates are papillate, are homothallic, possess 80 to 86% amphigynous antheridia, and have a maximum temperature for growth of 36.5 degrees C. Isozyme analysis of the Phytophthora sp-h isolates revealed a three-banded pattern with malic enzyme and a three-banded pattern with malate dehydrogenase on the second putative locus. The fastest band at both enzyme loci comigrated with the single P. nicotianae band, the slowest band comigrated with the single P. cactorum (and also P. pseudotsugae) band, and one band in between was concluded to represent the heterodimeric isozyme. The random amplified polymorphic DNA patterns of the Phytophthora sp-h isolates almost exclusively consisted of bands that were also present in either P. nicotianae or P. cactorum. Southern hybridization showed that bands specific for P. nicotianae were present as comigrating bands in the Phytophthora sp-h isolates. The same was found for species-specific bands of P. cactorum. It is concluded that the three Phytophthora sp-h isolates represent interspecific hybrids, P. nicotianae being the one parent and P. cactorum the other. Analysis of mito-chondrial DNA with restriction enzymes revealed banding patterns in all the Phytophthora sp-h isolates identical with those of P. nicotianae, confirming that indeed P. nicotianae was one of the parents.
摘要 从患病的马蹄莲和报春花植物中分离出了 3 个相似的疫霉属（Phytophthora sp-h）分离株。培养特性与任何已知的疫霉菌种描述都不相符。Phytophthora sp-h 分离株呈乳头状，同宗配合，具有 80-86%的雌雄同体的游动配子囊，最适生长温度为 36.5°C。Phytophthora sp-h 分离株的同工酶分析显示，在第二个假定的位点上，苹果酸酶和苹果酸脱氢酶均呈现出三带模式。在两个酶位点上，最快的带与单个 P. nicotianae 带迁移，最慢的带与单个 P. cactorum（也与 P. pseudotsugae）带迁移，中间的一条带被认为是异源二聚体同工酶。Phytophthora sp-h 分离株的随机扩增多态性 DNA 图谱几乎完全由在 P. nicotianae 或 P. cactorum 中也存在的条带组成。Southern 杂交显示，Phytophthora sp-h 分离株中存在与 P. nicotianae 特异性条带相同的迁移条带。P. cactorum 的种特异性条带也是如此。结论是，这 3 个 Phytophthora sp-h 分离株代表种间杂种，P. nicotianae 是一个亲本，P. cactorum 是另一个亲本。用限制性内切酶分析线粒体 DNA 显示，所有 Phytophthora sp-h 分离株的带型与 P. nicotianae 的带型完全相同，证实 P. nicotianae 确实是亲本之一。
