Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa.
Stud Mycol. 2006;55:255-67. doi: 10.3114/sim.55.1.255.
In a survey for Cryphonectria and Chrysoporthe species on Myrtales in South Africa, a fungus resembling the stem canker pathogen Chrysoporthe austroafricana was collected from native Syzygium cordatum near Tzaneen (Limpopo Province), Heteropyxis canescens near Lydenburg (Mpumalanga Province) and exotic Tibouchina granulosa in Durban (KwaZulu-Natal Province). The fungus was associated with dying branches and stems on S. cordatum, H.canescens and T.granulosa. However, morphological differences were detected between the unknown fungus from these three hosts and known species of Chrysoporthe. The aim of this study was to characterise the fungus using DNA sequence comparisons and morphological features. Pathogenicity tests were also conducted to assess its virulence on Eucalyptus (ZG 14 clones), H.natalensis and T. granulosa. Plants of H. canescens were not available for inoculation. Results showed distinct morphological differences between the unknown fungus and Chrysoporthe spp. Phylogenetic analysis showed that isolates reside in a clade separate from Chrysoporthe and other related genera. Celoporthe dispersa gen. et sp. nov. is, therefore, described to accommodate this fungus. Pathogenicity tests showed that C.dispersa is not pathogenic to H. natalensis, but that it is a potential pathogen of Eucalyptus and Tibouchina spp.
在南非桃金娘目上对 Cryphonectria 和 Chrysoporthe 物种的调查中，一种类似于茎溃疡病原体 Chrysoporthe austroafricana 的真菌从 Tzaneen（林波波省）附近的本地 Syzygium cordatum、Lydenburg（姆普马兰加省）附近的 Heteropyxis canescens 和德班的外来 Tibouchina granulosa 中采集到。该真菌与 S. cordatum、H.canescens 和 T.granulosa 上死亡的树枝和茎有关。然而，在这三个宿主中的未知真菌与已知的 Chrysoporthe 物种之间检测到了形态差异。本研究的目的是使用 DNA 序列比较和形态特征来表征该真菌。还进行了致病性测试，以评估其对桉树（ZG 14 克隆）、H.natalensis 和 T.granulosa 的毒力。H. canescens 的植物不可用于接种。结果表明，未知真菌与 Chrysoporthe spp.之间存在明显的形态差异。系统发育分析表明，分离株与 Chrysoporthe 和其他相关属位于不同的分支。因此，描述了 Celoporthe dispersa gen. et sp. nov. 以容纳这种真菌。致病性测试表明，C.dispersa 对 H. natalensis 没有致病性，但它是桉树和 Tibouchina spp.的潜在病原体。
