Grube Martin, Hawksworth David L
Institut für Pflanzenwissenschaften, Karl-Franzens Universität Graz, Holteigasse 6, A-8010 Graz, Austria.
Mycol Res. 2007 Sep;111(Pt 9):1116-32. doi: 10.1016/j.mycres.2007.04.008. Epub 2007 May 13.
Following discussions of the definition of the terms 'lichen' and 'thallus', the role of lichenization in the evolution of asco- and basidiomycetes, and divergence and convergence in fruit body types, the morphogenetic interpretation of types of thallus form in lichens is reviewed. Attention is drawn to the various morphogenetic hypotheses proposed to explain the lichen thallus, but it is concluded that it is best interpreted as a novel phenotype with no exact homologue. Similar ascomatal and thallus types are found in lichen-forming fungi of different orders and families, as now revealed by molecular phylogenetic studies. These are interpreted as examples of convergent evolution, strategies by which unrelated fungi either display captured algae to maximize photosynthetic opportunities, or to attach themselves to a substratum. Phenotypic evolution of fruit body and thallus types in the major orders and clades is summarized, and the thallus types known in each order are tabulated. An hypothesis relating the evolution of these structures to hygroscopic movements is proposed, and the critical position of lichens in developing an integrated approach to ascomycete evolution is emphasized.
在对“地衣”和“叶状体”术语的定义、地衣化在子囊菌和担子菌进化中的作用以及子实体类型的趋异和趋同进行讨论之后，对地衣中叶状体形态类型的形态发生学解释进行了综述。文中提请注意为解释地衣叶状体而提出的各种形态发生学假说，但得出的结论是，最好将其解释为一种没有确切同源物的新表型。分子系统发育研究现已表明，在不同目和科的地衣形成真菌中发现了相似的子囊盘和叶状体类型。这些被解释为趋同进化的例子，即不相关的真菌通过展示捕获的藻类以最大化光合作用机会或附着在基质上的策略。总结了主要目和类群中子实体和叶状体类型的表型进化，并列出了每个目中已知的叶状体类型。提出了一个将这些结构的进化与吸湿运动相关联的假说，并强调了地衣在发展子囊菌进化综合方法中的关键地位。
