Lawrey James D, Lücking Robert, Sipman Harrie J M, Chaves José L, Redhead Scott A, Bungartz Frank, Sikaroodi Masoumeh, Gillevet Patrick M
Department of Environmental Science and Policy, George Mason University, Fairfax, VA 22030-4444, USA.
Mycol Res. 2009 Oct;113(Pt 10):1154-71. doi: 10.1016/j.mycres.2009.07.016. Epub 2009 Jul 29.
The Agaricales is the largest and most diverse order of mushroom-forming Basidiomycota, with over 100 natural groups recognized in recent Fungal Tree of Life studies. Most agarics are either saprotrophic or ectomycorrhizal fungi, but the family Hygrophoraceae is in part characterized by a unique and remarkable diversity of lichenized forms. The most familiar of these is the chlorolichen genus Lichenomphalia, whose phylogenetic position in the Agaricales has been established. Recent limited evidence suggested that Hygrophoraceae also contains cyanolichens in the genus Dictyonema, which indicates a remarkable concentration and diversity of lichen-formers in a single family of agarics. To demonstrate the relationships of lichen-formers to other fungi in the family, we assembled ribosomal sequences from 52 species representing recognized groups within the Hygrophoraceae, among them new sequences representing Acantholichen and most species and forms of Dictyonema. The molecular data were evaluated using parsimony, likelihood, Bayesian, and distance analyses, including coding of ambiguous regions by means of INAASE and ARC, all of which indicate that Dictyonema and Acantholichen form a monophyletic clade derived from the primarily bryophilous genus Arrhenia and sister to the enigmatic Athelia pyriformis, a species unrelated to the Atheliales for which we are proposing a new genus name Eonema. The chlorolichen genus Lichenomphalia may be polyphyletic. Fungi in the Dictyonema-Acantholichen clade are typically tropical, entirely lichenized, and associate with cyanobacterial photobionts. Our data indicate a transition from agaricoid-omphalinoid basidiomes observed in Arrhenia to stereoid-corticioid forms in Dictyonema, and also support a previous suggestion of a connection between loss of clamp connections and lichenization. The diverse basidiome and thallus morphologies and nutritional ecologies of these fungi indicate a remarkable evolutionary flexibility that appears to have developed in part as a consequence of symbiosis.
伞菌目是形成蘑菇的担子菌门中最大且最多样化的目，在最近的“真菌生命树”研究中已识别出100多个自然类群。大多数伞菌是腐生菌或外生菌根真菌，但蜡伞科部分以独特且显著多样的地衣化形式为特征。其中最常见的是绿藻地衣属的地卷菌，其在伞菌目中的系统发育位置已确定。最近有限的证据表明，蜡伞科还包含网衣属的蓝藻地衣，这表明在一个单一的伞菌科中地衣形成者的显著集中和多样性。为了证明地衣形成者与该科中其他真菌的关系，我们从代表蜡伞科内已识别类群的52个物种中组装了核糖体序列，其中包括代表刺孢地衣以及网衣属的大多数物种和形态的新序列。使用简约法、似然法、贝叶斯法和距离分析法对分子数据进行了评估，包括通过INAASE和ARC对模糊区域进行编码，所有这些都表明网衣属和刺孢地衣形成了一个单系分支，该分支源自主要喜苔藓的阿伦菌属，并且是梨形无柄盘菌的姐妹群，梨形无柄盘菌是一个与无柄盘菌目无关的物种，我们正在为其提议一个新的属名“始盘菌属”。绿藻地衣属地卷菌可能是多系的。网衣属 - 刺孢地衣分支中的真菌通常是热带的，完全地衣化，并与蓝藻光合生物共生。我们的数据表明，在阿伦菌属中观察到的从伞菌状 - 脐菇状担子果向网衣属中的立体状 - 革菌状形式的转变，并且还支持了之前关于锁状联合的丧失与地衣化之间联系的建议。这些真菌多样的担子果和菌体形态以及营养生态表明了一种显著的进化灵活性，这种灵活性似乎部分是共生的结果而发展起来的。
