Stands of the landscape‐dominant tree, Metrosideros polymorpha (‘ōhi‘a) on the Island of Hawai‘i, HI., USA, are dying from a phenomenon known as rapid ‘ōhi‘a death (ROD). Approximately 180,000 acres of forest have already been impacted by the disease, the majority of which is attributed to C. lukuohia, the more aggressive of the two Ceratocystis species responsible for ROD. Three isolates of C. lukuohia were compared for differences in aggressiveness. Mean disease severity and mean number of days to death did not differ among the three isolates of C. lukuohia. A single isolate was selected for use in a resistance screening of 128 plants across four varieties of M. polymorpha occurring on Hawai‘i Island: incana, glaberrima, polymorpha and newellii. Disease severity was lower in early‐successional var. incana (38.84%) and riparian var. newellii (36.11%) compared to late‐successional var. glaberrima (61.27%) and high‐elevation var. polymorpha (70.27%). Var. incana and var. newellii also had the lowest mortality (63% and 77%, respectively) while var. glaberrima (86%) and var. polymorpha (100%) had the highest mortality. Eighty‐five per cent of the plants that died did so within 49 days post‐inoculation and mean number of days to death was significantly higher for var. glaberrima (46) compared to var. polymorpha (31). The results of this preliminary study suggest that some form of resistance might be present in natural populations of at least one variety of M. polymorpha on Hawai‘i Island and should be investigated more intensively.

中文翻译：

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筛选大麦蝇（Metrosideros polymorpha（'ōhi'a））变种对绿褐藻的抗性

美国夏威夷州夏威夷岛上以景观为主的树种Metrosideros polymorpha（'ōhi'a）濒临灭绝，这种现象被称为快速'ōhi'a死亡（ROD）的现象所致。该病已经影响了大约180,000英亩的森林，其中大部分归因于C. lukuohia，这是造成ROD的两种Ceratocystis物种中更具侵略性的一种。比较了三种分离的C. lukuohia侵略性的差异。三种克鲁维氏菌的平均疾病严重度和平均死亡天数没有差异。选择单个分离株用于筛选四种多形吗啡的128种植物的抗性发生在夏威夷岛上：incana，glaberrima，polymorpha和newellii。早期手术变种的疾病严重程度较低。印第安那（38.84％）和河岸变种。newellii（36.11％）相较于后续成功变种 glaberrima（61.27％）和高海拔var。多形体（70.27％）。变体 incana和var。纽瓦莱州的死亡率也最低（分别为63％和77％）。glaberrima（86％）和var。多形体（100％）的死亡率最高。死亡的植物中有百分之八十五是在接种后49天内这样做的，而平均死亡天数明显高于var。glaberrima（46）与var。多形体（31）。这一初步研究的结果表明，某种形式的阻力可能出现在至少一个多种自然种群M.多形上的夏威夷岛，应该更深入调查。