Molecular Systematic Study of the Boletales (Basidiomycetes)

加州大学伯克利分校的约翰·泰勒博士和博士后助理托马斯·布伦斯博士将采用现代分子技术来研究博莱塔目真菌之间的进化关系。他们将研究线粒体基因序列，构建线粒体和核糖体RNA基因的限制性内切酶酶切位点图，并对选定的核糖体RNA基因进行测序。初步结果表明，与传统形态学研究相比，这些方法可以更好地了解这些真菌之间的系统发育关系。这项工作之所以重要，有几个原因。许多待研究的物种是温带森林树木重要的外生菌根共生体，其他物种是重要的腐木菌。了解这些真菌的系统发育将有助于深入了解它们与植物宿主的共同进化模式，并将有助于更好地理解菌根共生体与该目初级物种之间的关系。根据目前的定义，Boletales包含几种形态不同的真菌群，包括假松露，鳃蘑菇和复生木腐真菌。因此，了解它们的系统发育将为检验关于担子菌真菌形态趋势的理论提供一个框架。最后，所使用的方法应该被证明适用于广泛的其他真菌群的进化研究，并且所产生的基因序列数据将添加到一个数据库中，该数据库最终可用于研究整个担子菌的进化系。

Dr. John Taylor and postdoctoral associate Dr. Thomas Bruns of the University of California at Berkeley will employ modern molecular techniques to investigate the evolutionary relationships among fungi of the order Boletales. They will study the mitochondrial gene order, construct restriction- endonuclease digestion-site maps of mitochondrial and nuclear ribosomal RNA genes, and sequence selected ribosomal RNA genes. Preliminary results suggest that a much better understanding of phylogenetic relationships among these fungi can be achieved with these methods than has been realized to date by traditional morphological studies. This work is significant for several reasons. Many of the species to be studied are important ectomycorrhizal root symbionts of temperate-forest trees, and others are important wood-rotters. An understanding of the phylogeny of these fungi will provide insight into their pattern of coevolution with their plant hosts, and will provide a better understanding of the relationship between mycorrhizal symbionts and primary saprobes in the order. As currently defined, the Boletales contains several morphologically diverse groups of fungi, including false truffles, gilled mushrooms, and resupinate wood-rot fungi. Therefore, understanding of their phylogeny will provide a framework for testing theories about morphological trends in the basidiomycete fungi. Finally, the methods being used should prove applicable to evolutionary investigations in a wide range of other groups of fungi, and the gene-sequence data generated will add to a database which can eventually be used to study the evolutionary lines within the entire Basidiomycetes.