Mycology and Nematology Genetic Diversity and Biology Laboratory, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Avenue, Beltsville, Maryland 20705.
Agricultural Research Service Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830.
Mycologia. 2021 May-Jun;113(3):643-652. doi: 10.1080/00275514.2021.1872869. Epub 2021 Mar 18.
var. is an endangered native Hawaiian plant, and part of the recovery plan includes repopulation using plants grown in a nursery. However, disease pressure from downy mildew is hindering repopulation efforts. The organism associated with the downy mildew was determined to be a species with brown, ellipsoid conidia measuring 21 by 16 µm on average, which was morphologically different from validly described species of that infect species, but it was morphologically similar to the invalidly published species (Art. 40.1). Comparison of mitochondrial cytochrome oxidase subunit I (1), mitochondrial cytochrome oxidase subunit II (2), nuclear internal transcribed spacer (ITS), and nuclear 28S rRNA D1-D2 (28S) loci revealed the unknown to be molecularly divergent from and , but very similar to from , the type host of . Phylogenetic trees inferred with maximum likelihood and Bayesian inference from a concatenated alignmaent and individual gene trees confirmed the divergence of the unknown from and and its similarity to . However, attempts to inoculate with the strain from var. were unsuccessful, which, in conjunction with divergence in ITS, suggests that the unknown is specific to var. . Herein, the strain on var. is described as the new species based on morphology, molecular phylogenetics, and host specificity. In addition, is described here to honor Nina Ivanova Gaponenko on the basis of her description of .
var. 是一种濒危的夏威夷本土植物，其恢复计划包括使用在苗圃中种植的植物进行重新造林。然而，霜霉病的压力阻碍了重新造林的努力。与霜霉病有关的生物体被确定为一种具有棕色、椭圆形分生孢子的 物种，平均长度为 21 乘 16 µm，其形态与感染 物种的有效描述的 物种不同，但与无效发表的物种 （Art. 40.1）形态相似。比较线粒体细胞色素氧化酶亚单位 I（1）、线粒体细胞色素氧化酶亚单位 II（2）、核内转录间隔区（ITS）和核 28S rRNA D1-D2（28S）基因座表明，未知的 与 和 在分子上是不同的，但与 非常相似，是 的模式宿主。基于串联比对和单个基因树的最大似然和贝叶斯推断得出的系统发育树证实了未知的 与 和 的分化及其与 的相似性。然而，试图用来自 var. 的菌株接种 是不成功的，这与 ITS 的分化表明未知的 是 var. 的特异性。在此，基于形态学、分子系统发育和宿主特异性，将 var. 上的 菌株描述为新物种 。此外，根据 Nina Ivanova Gaponenko 对 的描述，将 描述在这里。
