Molecular Systematic Investigation of Rust Fungi Associated with Pinaceae

锈菌是引起松树及其近缘针叶树几种重要经济病害的植物病原菌。锈菌的分类和系统发育是有争议的，因为它们很小，几乎没有明显的形态差异，而且它们有复杂的生活史，有几个产孢期。加州大学伯克利分校的托马斯·布鲁斯博士将利用现代分子技术研究主要科苦参科锈菌之间的进化关系。他已经开发出一种方法，可以从少量的真菌材料中进行特定的DNA扩增，即使是从保存下来的标本中也是如此，有了这种改进，植物宿主的DNA将不再干扰对真菌的研究。许多种锈菌的精选核基因和线粒体基因将被分析其核苷酸序列，并将使用计算机程序进行比较，以生成相关物种的可能系统发育框架。然后，将这样构建的真菌系统发育图与目前松树物种系统发育的概念进行比较，以检验真菌寄生虫和寄主松树在地质年代中是相互关联(“共同进化”)进化的。此外，分子分析将提供单个锈菌物种的独特遗传标记，对于在其他分类学和生态学研究中准确鉴定的目的有价值。

The rust fungi are plant pathogens that are responsible for several economically important diseases of pines and their conifer relatives. The taxonomy and phylogeny of rust fungi are controversial because the organisms are small, with few discernible morphological differences, and they have complex life histories with several spore-bearing stages. Dr. Thomas Bruns of the University of California-Berkeley will use modern molecular techniques to investigate evolutionary relationships among rust fungi of the major family Melampsoraceae. He has developed methods that allow specific amplification of DNA from small amounts of fungal material, even from preserved specimens, and with this refinement plant-host DNA will no longer interfere with the study of the fungus. Selected nuclear and mitochondrial genes of numerous species of rust fungi will be analyzed for their nucleotide sequences, and these will be compared using computer programs to generate a likely phylogenetic framework for related species. The phylogeny thus constructed for the fungi will then be compared to current notions of pine species phylogeny to test the idea that fungal parasites and host pines have evolved in association ("coevolution") through geological time. In addition, the molecular analyses will provide unique genetic markers of individual rust-fungus species, valuable for purposes of accurate identification in other taxonomic and ecological studies.