Abstract

Over the past 15 years, downy mildew became the most destructive foliar disease in cultivated Impatiens species (Balsaminaceae) worldwide. A previous study had revealed that the causal agent was not Plasmopara obducens (Oomycota, Peronosporales) but Plasmopara destructor on Impatiens walleriana, and Plasmopara velutina on Impatiens balsamina. This hints to a relatively high degree of specialization of Plasmopara on Balsaminaceae. Therefore, it was the aim of the present study to perform multigene phylogenetic analysis and detailed morphological investigation for several Korean downy mildew samples parasitic to cultivated I. walleriana, and I. balsamina, but also to a northeast Asian wild plant, Impatiens textori. It was revealed that I. textori harbors a new species, which is introduced and described here as Plasmopara elegantissima.

 抽象的

在过去的 15 年里，霜霉病已成为全球栽培凤仙花（凤仙花科）最具破坏性的叶部病害。先前的一项研究表明，致病因子不是Obducens （卵菌门、霜霉目），而是Impatiens walleriana上的Plasmopara destructor和Impatiens balsamina上的Plasmopara velutina 。这暗示了凤仙花科单轴霉具有相对较高的专业化程度。因此，本研究的目的是对寄生于栽培I. walleriana和I. balsamina以及东北亚野生植物Impatiens textori的几个韩国霜霉病样品进行多基因系统发育分析和详细形态学调查。据透露， I.textori拥有一个新物种，本文将其引入并描述为优雅单轴霉 (Plasmopara beautifulissima) 。