Aime M Catherine, Urbina Hector, Liber Julian A, Bonito Gregory, Oono Ryoko
a Department of Botany and Plant Pathology , Purdue University , West Lafayette , Indiana 47907.
b Department of Plant, Soil and Microbial Sciences , Michigan State University , East Lansing , Michigan 48824.
Mycologia. 2018 Jan-Feb;110(1):136-146. doi: 10.1080/00275514.2018.1446650.
Sterile fungal isolates are often recovered in leaf and root endophytic studies, although these seldom play a significant role in downstream analyses. The authors sought to identify and characterize two such endophytes-one representing the most commonly recovered fungal isolate in recent studies of needle endophytes of Pinus taeda and the other representing a rarely isolated root endophyte of Populus trichocarpa. Both are shown by DNA sequencing to be undescribed species of Atractiellomycetes (Pucciniomycotina, Basidiomycota), a poorly characterized class of mostly plant-associated and presumably saprobic microfungi. The authors describe the new genus and species Atractidochium hillariae (Phleogenaceae) and the new species Proceropycnis hameedii (Hoehnelomycetaceae), both in the Atractiellales, to accommodate these unusual isolates. Following incubations of 1-2 mo, A. hillariae produces minute white sporodochia, similar to those produced by several other members of Atractiellales, whereas Pr. hameedii forms conidia singly or in chains in a manner similar to its sister species Pr. pinicola. Additionally, we provide a taxonomic revision of Atractiellomycetes based on multilocus analyses and propose the new genera Neogloea (Helicogloeaceae) and Bourdotigloea (Phleogenaceae) to accommodate ex-Helicogloea species that are not congeneric with the type H. lagerheimii. Atractiellomycetes consists of a single order, Atractiellales, and three families, Hoehnelomycetaceae, Phleogenaceae, and Helicogloeaceae. Accumulated evidence suggests that Atractiellomycetes species are common but infrequently isolated members of plant foliar and root endobiomes.
在叶片和根部内生菌研究中，常常能分离出无菌真菌菌株，不过这些菌株在下游分析中很少发挥重要作用。作者试图鉴定和描述两种这样的内生菌——一种是在近期火炬松针叶内生菌研究中最常分离出的真菌菌株，另一种是很少分离到的毛果杨根部内生菌。通过DNA测序表明，这两种菌株均为未描述过的无柄孢菌目（担子菌门，锈菌亚门）物种，这是一类特征描述较少的微真菌，大多与植物相关，可能为腐生菌。作者描述了新属新种希氏无柄孢菌属（Phleogenaceae科）和新种哈米迪原扁孔菌（Hoehnelomycetaceae科），二者均属于无柄孢菌目，以容纳这些不寻常的分离菌株。经过1 - 2个月的培养，希氏无柄孢菌会产生微小的白色分生孢子盘，类似于无柄孢菌目中其他几个成员产生的分生孢子盘，而哈米迪原扁孔菌则以类似于其姊妹种松生原扁孔菌的方式单独或成链产生分生孢子。此外，我们基于多位点分析对无柄孢菌目进行了分类修订，并提出了新属新球黏菌属（Helicogloeaceae科）和布尔迪黏菌属（Phleogenaceae科），以容纳那些与模式种拉氏黏菌不同属的原黏菌属物种。无柄孢菌目由单一目——无柄孢菌目和三科——Hoehnelomycetaceae科、Phleogenaceae科和Helicogloeaceae科组成。积累的证据表明，无柄孢菌目物种是植物叶部和根部内生菌群落中常见但很少分离到的成员。
