University of Tennessee, Genome Science and Technology Graduate Program, Knoxville, TN, USA.
Persoonia. 2010 Dec;25:109-16. doi: 10.3767/003158510X551763. Epub 2010 Dec 14.
Several filamentous oomycete species of the genus Halophytophthora have recently been described from marine environments, mostly from subtropical and tropical ecosystems. During a survey of oomycetes from leaf litter of Spartina alterniflora in salt marshes of southeastern Georgia, isolates of four taxa were recovered that bore similarity to some members of Halophytophthora but were highly divergent from isolates of Halophytophthora s.str. based on a combined sequence analysis of two nuclear loci. In phylogenetic analyses, these isolates were placed basal to a monophyletic group comprised of Pythium of the Pythiaceae and the Peronosporaceae. Sequence and morphology of these taxa diverged from the type species Halophytophthora vesicula, which was placed within the Peronosporaceae with maximum support. As a consequence a new family, the Salisapiliaceae, and a new genus, Salisapilia, are described to accommodate the newly discovered species, along with one species previously classified within Halophytophthora. Morphological features that separate these taxa from Halophytophthora are a smaller hyphal diameter, oospore production, lack of vesicle formation during sporulation, and a plug of hyaline material at the sporangial apex that is displaced during zoospore release. Our findings offer a first glance at the presumably much higher diversity of oomycetes in estuarine environments, of which ecological significance requires further exploration.
最近，从海洋环境中发现了几个属于海生植物疫霉属的丝状卵菌物种，这些物种主要来自亚热带和热带生态系统。在对佐治亚州东南部盐沼的互花米草叶凋落物中的卵菌进行调查时，回收了四个分类群的分离物，这些分离物与海生植物疫霉属的某些成员相似，但与海生植物疫霉属的分离物高度不同，因为基于两个核基因座的组合序列分析。在系统发育分析中，这些分离物位于一个单系群的基础上，该群由 Pythiaceae 和 Peronosporaceae 的 Pythium 组成。这些分类群的序列和形态与模式种海生植物疫霉属的海生植物疫霉属有很大的不同，后者被放置在 Peronosporaceae 中，支持度最高。因此，为了容纳新发现的物种，描述了一个新的科 Salisapiliaceae 和一个新的属 Salisapilia，以及一个以前分类在海生植物疫霉属中的物种。这些分类群与海生植物疫霉属分离的形态特征是菌丝直径较小、卵孢子的产生、在孢子形成过程中缺乏泡囊的形成，以及在游动孢子释放时位于游动孢子囊顶端的透明物质塞被移位。我们的发现首次揭示了河口环境中卵菌的多样性可能更高，其生态意义需要进一步探索。
