Science Division, Department of Environment and Conservation, Locked Bag 104, Bentley Delivery Centre, WA 6983, Australia.
IMA Fungus. 2013 Jul;4(1):111-22. doi: 10.5598/imafungus.2013.04.01.11. Epub 2013 Jun 10.
Morphological and DNA sequence characteristics of a pathogenic fungus isolated from branch cankers in Proteaceae of the South West Australian Floristic Region elucidated a new genus and species within Cryphonectriaceae (Diaporthales). The pathogen has been isolated from canker lesions in several Banksia species and Lambertia echinata subsp. citrina, and is associated with a serious decline of the rare B. verticillata. Lack of orange pigment in all observed structures except cirrhi, combined with pulvinate to globose black semi-immersed conidiomata with paraphyses, distinguishes the canker fungus from other genera of Cryphonectriaceae. This was confirmed by DNA sequence analysis of the ITS regions, β-tubulin, and LSU genes. The fungus (sexual morph unknown) is described as Luteocirrhus shearii gen. sp. nov. Lesions in seedlings of Banksia spp. following wound inoculation and subsequent recovery confirm Koch's postulates for pathogenicity. This pathogen of native Proteaceae is currently an emerging threat, particularly toward B. baxteri and B. verticillata.
从西南澳大利亚植物区系的 Proteaceae 树枝溃疡中分离出的一种致病真菌的形态学和 DNA 序列特征,阐明了 Cryphonectriaceae(Diaporthales)内的一个新属和新种。该病原体已从几种 Banksia 物种和 Lambertia echinata subsp. citrina 的溃疡病变中分离出来,与珍稀 Banksia verticillata 的严重衰退有关。除了卷须外,所有观察到的结构都缺乏橙色色素,加上具假侧丝的盘状到球形黑色半埋生分生孢子器,将溃疡真菌与 Cryphonectriaceae 的其他属区分开来。这通过 ITS 区、β-微管蛋白和 LSU 基因的 DNA 序列分析得到了证实。该真菌(未知有性形态)被描述为 Luteocirrhus shearii 新属新种。在 Banksia spp. 的幼苗中进行伤口接种和随后恢复后的病变,证实了致病性的科赫假设。这种本地 Proteaceae 的病原体目前是一种新出现的威胁,特别是对 B. baxteri 和 B. verticillata。