The Serendipitaceae family was erected in 2016 to accommodate the Sebacinales ‘group B’ clade, which contains peculiar species of cultivable root–associated fungi involved in symbiotic associations with a wide range of plant species. Here we report the isolation of a new Serendipita species which was obtained from protocorms of the terrestrial orchid Epidendrum fulgens cultivated in a greenhouse. This species is described based on phylogenetic analysis and on its microscopic and ultrastructural features in pure culture and in association with the host’s protocorms. Its genome size was estimated using flow cytometry, and its capacity to promote the germination of E. fulgens seeds and to associate with roots of Arabidopsis thaliana was also investigated. Serendipita restingae sp. nov. is closely related to Serendipita sp. MAFF305841, isolated from Microtis rara (Orchidaceae), from which it differs by 14.2% in the ITS region and by 6.5% in the LSU region. It produces microsclerotia formed of non-monilioid hyphae, a feature that was not reported for the Sebacinales hitherto. Serendipita restingae promoted the germination of E. fulgens seeds, forming typical mycorrhizal pelotons within protocorm cells. It was also able to colonize the roots of Arabidopsis thaliana under in vitro conditions. Arabidopsis plants grown in association with S. restingae increased their biomass more than fourfold. Serendipita restingae is the first Serendipitaceae species described for the Americas.

Serendipitaceae家族于2016年竖立，以容纳Sebacinales的“ B”类进化枝，其中包含可培养的根相关真菌的奇特物种，这些真菌与多种植物物种共生。在这里，我们报告了一种新的Serendipita物种的分离，该物种是从温室中栽培的陆地兰花表皮石ful的原球茎获得的。基于系统发育分析及其在纯培养中以及与寄主的原球茎相关的微观和超微结构特征，对该物种进行了描述。使用流式细胞仪评估了其基因组大小，并具有促进E. fulgens种子萌发并与拟南芥根结合的能力。还进行了调查。Serendipita Restingae sp。十一月 与Serendipita sp。密切相关。MAFF305841，是从中华绒螯蟹（Microtis rara）（兰科）中分离出来的，与ITS区域的差异为14.2％，在LSU区域的差异为6.5％。它产生的非菌丝状菌丝形成了菌核，这是迄今尚未报道的Sebacinales的特征。Serendipita Restae促进了E. fulgens种子的萌发，在原球茎细胞内形成典型的菌根果胶。它也能够在体外条件下在拟南芥的根部定植。与S. restae相关的拟南芥植物使其生物量增加了四倍以上。Serendipitaceae科是描述于美洲的第一个Serendipitaceae科。