University of Maryland, Department of Plant Science and Landscape Architecture, 2112 Plant Sciences Building, College Park, Maryland, 20742, USA.
U.S. Department of Agriculture, Agricultural Research Service, Mycology and Nematology Genetic Diversity and Biology Laboratory, 10300 Baltimore Avenue, Beltsville, Maryland, 20705, USA.
Sci Rep. 2019 Sep 3;9(1):12685. doi: 10.1038/s41598-019-48943-2.
Many aspects of the dynamics of tropical fungal endophyte communities are poorly known, including the influence of host taxonomy, host life stage, host defence, and host geographical distance on community assembly and composition. Recent fungal endophyte research has focused on Hevea brasiliensis due to its global importance as the main source of natural rubber. However, almost no data exist on the fungal community harboured within other Hevea species or its sister genus Micrandra. In this study, we expanded sampling to include four additional Hevea spp. and two Micrandra spp., as well as two host developmental stages. Through culture-dependent and -independent (metagenomic) approaches, a total of 381 seedlings and 144 adults distributed across three remote areas within the Peruvian Amazon were sampled. Results from both sampling methodologies indicate that host developmental stage had a greater influence in community assemblage than host taxonomy or locality. Based on FunGuild ecological guild assignments, saprotrophic and mycotrophic endophytes were more frequent in adults, while plant pathogens were dominant in seedlings. Trichoderma was the most abundant genus recovered from adult trees while Diaporthe prevailed in seedlings. Potential explanations for that disparity of abundance are discussed in relation to plant physiological traits and community ecology hypotheses.
热带真菌内生菌群落的许多动态方面知之甚少，包括宿主分类学、宿主生活阶段、宿主防御和宿主地理距离对群落组装和组成的影响。由于巴西橡胶树是天然橡胶的主要来源，具有全球重要性，因此最近的真菌内生菌研究集中在巴西橡胶树上。然而，关于其他巴西橡胶树物种或其姊妹属 Micrandra 内的真菌群落几乎没有数据。在这项研究中，我们扩大了采样范围，包括另外四个巴西橡胶树种和两个 Micrandra 种，以及两个宿主发育阶段。通过依赖培养和非依赖培养（宏基因组）的方法，总共从秘鲁亚马逊地区的三个偏远地区采集了 381 株幼苗和 144 株成年树。两种采样方法的结果都表明，宿主发育阶段对群落组装的影响大于宿主分类学或地点。根据 FunGuild 生态类群的分配，腐生和菌寄生内生菌在成年树上更为常见，而植物病原菌在幼苗中占优势。从成年树上回收的最丰富的属是 Trichoderma，而 Diaporthe 在幼苗中占优势。关于这种丰度差异的潜在解释，将结合植物生理特性和群落生态学假设进行讨论。
