Benavent-Celma Clara, McLaggan Debbie, van West Pieter, Woodward Steve
Department of Plant and Soil Science, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, Scotland, UK.
International Centre for Aquaculture Research and Development (ICARD), Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
J Fungi (Basel). 2023 May 29;9(6):627. doi: 10.3390/jof9060627.
The oomycete genus includes many plant pathogens important in agricultural and environmental systems. Natural interspecific hybridization has been reported several times in , and although the fundamental processes of interspecific hybridization and the consequences of subsequent ecological distribution are poorly understood, reports suggest some hybrids can infect a broader host range and display enhanced virulence compared to the putative parental species. During a survey carried out at the University of Aberdeen in 2014-2015, of oomycetes present in ornamental plants purchased via the internet, a batch of oomycete isolates remained unidentified, showing, in some isolates, features generally related to hybridization. The aim of this study was to determine whether hybridization events had occurred between endemic and introduced oomycetes, probably/possibly facilitated through the international plant trade. The list of isolates examined included a putative hybrid closely related to . The putative hybrid isolate was further characterized, and pathogenicity were tests carried out on , using an isolate of as a positive control. Cloning of ITS, COXI and β-tubulin genes resulted in different sequence versions of the putative hybrid isolate; after mapping and a polymorphism position comparison, it was concluded that the studied isolate contained genetic information from , , , and . A PCR-RFLP assay, a NEBcutter analysis and flow cytometry analysis (genomes ranged between 0.168 to 0.269 pg/2C) added further evidence of the hybrid nature of this isolate. The putative hybrid presented complex growing patterns ranging from rosaceous to chrysanthemum-like and had an optimum growth temperature of 25 °C. Although the putative hybrid produced visible symptoms of disease on seedlings, assessment of the relative susceptibility of to and the putative hybrid indicated that was significantly more virulent than the putative hybrid, based on mortality, disease severity and foliar symptoms.
卵菌纲属包括许多在农业和环境系统中重要的植物病原体。在[具体对象]中已多次报道了自然种间杂交，尽管种间杂交的基本过程以及随后生态分布的后果尚不清楚，但报告表明，一些杂种与假定的亲本物种相比，可以感染更广泛的宿主范围并表现出更强的毒力。在2014 - 2015年阿伯丁大学进行的一项调查中，对通过互联网购买的观赏植物中存在的卵菌进行了研究，一批卵菌分离株仍未鉴定出来，在一些分离株中显示出通常与杂交相关的特征。本研究的目的是确定本地和引入的卵菌之间是否发生了杂交事件，这可能/可能是通过国际植物贸易促成的。所检查的分离株列表包括一个与[具体物种]密切相关的假定杂种。对假定的杂种分离株进行了进一步表征，并以[具体物种]的一个分离株作为阳性对照，对[具体植物]进行了致病性测试。ITS、COXI和β -微管蛋白基因的克隆产生了假定杂种分离株的不同序列版本；在进行图谱绘制和多态性位置比较后，得出所研究的分离株包含来自[多个物种名称]的遗传信息。PCR - RFLP分析、NEBcutter分析和流式细胞术分析（基因组范围在0.168至0.269 pg/2C之间）进一步证明了该分离株的杂种性质。假定杂种呈现出从蔷薇状到菊花状的复杂生长模式，最佳生长温度为25℃。尽管假定杂种在[具体植物]幼苗上产生了明显的病害症状，但对[具体植物]对[具体物种]和假定杂种的相对易感性评估表明，基于死亡率、病害严重程度和叶片症状，[具体物种]比假定杂种的毒力明显更强。
