Qongqo Axola, Nchu Felix, Geerts Sjirk
Centre for Invasion Biology Department of Conservation and Marine Sciences Cape Peninsula University of Technology Cape Town South Africa.
South African National Biodiversity Institute Kirstenbosch Research Centre Cape Town South Africa.
Ecol Evol. 2022 Jul 14;12(7). doi: 10.1002/ece3.9100. eCollection 2022 Jul.
Fungal invasions only recently started to receive more attention in invasion biology. This is largely attributed to little or non-existent information about these inconspicuous organisms. Most invasion hypotheses focus on factors that increase invasion success; few try to explain why invasions fail. Here we hypothesize that a host-pathogen relationships can limit the invasiveness of an alien plant species in a novel range. To test this, we investigate whether the invasiveness of the Australian genus of Proteaceae, in South Africa is determined by the alien and major invasive phytopathogen, . The presence of in root and soil was evaluated using morphological and molecular techniques. Isolates were cultured onto selective media and polymerize chain reactions and internal transcribing spacers were used for identification. Acetone leaf extracts of 11 spp. were screened for antimicrobial activity against , using the minimum inhibitory concentration assay. A total of 3840 individuals from seven localities were surveyed. was consistently isolated from species root and soil samples. Out of the 12 species that were screened for antimicrobial activity, four introduced species, , , , and and the invasive and exhibited relatively high antimicrobial activity against (strain 696/12). We show that the phytopathogen in the native range has similar impact in the novel range and in doing so may limit invasion success of species with low antimicrobial activity.
真菌入侵在入侵生物学中直到最近才开始受到更多关注。这主要归因于关于这些不显眼生物的信息很少或根本不存在。大多数入侵假说关注的是增加入侵成功的因素；很少有人试图解释入侵失败的原因。在这里，我们假设宿主 - 病原体关系可以限制外来植物物种在新区域的入侵性。为了验证这一点，我们研究了南非山龙眼科澳大利亚属的入侵性是否由外来的主要入侵植物病原体决定。使用形态学和分子技术评估该病原体在植物根系和土壤中的存在情况。将分离物培养在选择性培养基上，并使用聚合酶链反应和内部转录间隔区进行鉴定。使用最低抑菌浓度测定法，对11种该属植物的丙酮叶提取物进行了针对该病原体的抗菌活性筛选。对来自七个地点的总共3840个个体进行了调查。该病原体始终能从该属植物的根系和土壤样本中分离出来。在筛选抗菌活性的12种该属植物中，四种外来物种、以及入侵性的和对该病原体（菌株696/12）表现出相对较高的抗菌活性。我们表明，原生范围内的植物病原体在新区域具有类似的影响，并且这样做可能会限制抗菌活性低的该属植物物种的入侵成功。
