Taxonomic and life cycle reappraisals of the marine basidiomycete <i>Nia vibrissa</i> complex, with descriptions of three new <i>Nia</i> species

The marine basidiomycete <i>Nia vibrissa</i> has been regarded as a species complex, possibly including several species, because morphological variations in fruitbody, spore, and spore appendage have been observed in materials from worldwide collections. Using more than 50 monosporic isolates of <i>N. vibrissa</i>–like fungi mainly obtained from Japanese beach coasts, we investigated their molecular phylogeny, morphological characteristics, mating compatibility, nuclear behavior during spore formation, and life cycles. Molecular phylogenetic analyses separated the examined strains into seven clades. Each clade of fungi exhibited distinctive characteristics in fruitbodies and spores produced by culturing monokaryotic strains and mated dikaryotic strains; these characteristics included the color of fruitbodies, apical structure of peridial hair hyphae, spore shape, and apical structure of spore appendages. Mating tests of monokaryotic strains demonstrated mating compatibility between strains within a clade and incompatibility among clades. Therefore, each clade of fungi was phylogenetically, morphologically, and biologically recognized as a different <i>Nia</i> species. Observation of the type specimen of <i>N. vibrissa</i> revealed a tiny T-shaped apical structure of spore appendages—not mentioned in the original description—that is unique to the species. This finding, together with the original description, suggests that our studied strains include <i>N</i>. aff. <i>vibrissa</i>, whose morphology is mostly identical to <i>N. vibrissa</i> sensu stricto, and three new species. Thus, we describe three new <i>Nia</i> species and propose emendation of the descriptions of the genus <i>Nia</i>. Culture-based studies have demonstrated that <i>Nia</i> species have both sexual and asexual morphs that produce morphologically similar fruitbodies (basidiomata and conidiomata) and spores (basidiospores and conidia). Because it has both morphs forming appendaged waterborne basidiospores and conidia, <i>Nia</i> must be the most well-adapted marine basidiomycete, ensuring the continuation of new generations by two morphs, while distributing in and inhabiting numerous marine environments.海洋担子菌振动诺氏孢菌（Nia vibrissa）曾被视为一个物种复合群，可能包含多个物种，因全球采集的标本中均观察到其子实体、孢子及孢子附属物存在形态变异。本研究以主要采自日本沿海海滩的50余株类振动诺氏孢菌单孢分离株（monosporic isolates）为材料，对其分子系统发育（molecular phylogeny）、形态特征、交配亲和性（mating compatibility）、孢子形成过程中的核行为（nuclear behavior）及生活史（life cycles）开展了系统研究。分子系统发育分析将供试菌株划分为7个进化支（clades）。各进化支的真菌在单核菌株培养及配对双核菌株所产生的子实体与孢子形态上均表现出独特性状，包括子实体颜色、包被毛菌丝（peridial hair hyphae）的顶端结构、孢子形状及孢子附属物的顶端结构。单核菌株的交配试验证实，同一进化支内的菌株间具有交配亲和性，而不同进化支间则存在交配不亲和性。据此，从系统发育、形态学及生物学特征来看，每个进化支均可被认定为一个独立的诺氏孢菌（Nia）物种。对振动诺氏孢菌的模式标本进行观察后发现，其孢子附属物存在一处此前原始描述未提及的小型T形顶端结构，该性状为该物种所特有。结合原始描述，该发现提示本研究的供试菌株包含形态上与狭义振动诺氏孢菌（N. vibrissa sensu stricto）基本一致的振动诺氏孢菌近似种（N. aff. vibrissa）以及3个新物种。据此，本研究描述了3个诺氏孢菌新物种，并提出修订诺氏孢菌属（Nia）的分类特征。基于培养的研究表明，诺氏孢菌（Nia）物种兼具有性型与无性型，可产生形态相似的子实体（担子果（basidiomata）与分生孢子果（conidiomata））及孢子（担孢子（basidiospores）与分生孢子（conidia））。由于该属真菌兼具可产生带附属物的水生担孢子与分生孢子的两种形态，诺氏孢菌（Nia）应是适应性最强的海洋担子菌类群，可通过两种形态维持种群延续，并广泛分布与栖息于各类海洋环境中。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于海洋担子菌Nia vibrissa复合体的分类学和生命周期重新评估，通过对超过50个单孢分离株的系统发育、形态和交配兼容性研究，识别出七个分支并描述了三个新Nia物种。研究还修订了Nia属的描述，揭示了其具有有性和无性形态，使其成为高度适应海洋环境的真菌，确保在多种海洋环境中繁殖和分布。