Phylogenetic and Biological Species in the Fusarium solani Complex

镰刀菌属中的盖瑟真菌作为植物和动物中的病原体、作为使食物和动物饲料中毒的毒素的产生者、作为具有潜在药物用途的化学品的创造性产生者、甚至作为人类消费的食物是极其重要的。 尽管它们的重要性，确定镰刀菌是非常困难的，因为他们提供了相对较少的形态特征，是有用的区分。 这导致了一个分类系统，在这个系统中，进化上截然不同的谱系（根据它们不能交配和形成孢子来判断）被集中在一起。 这个项目由宾夕法尼亚州立大学的大卫盖泽博士和他的美国农业部同事加里塞缪尔博士重点研究镰刀菌属物种复合体，这是一个由大约50个不同进化谱系组成的世界性群体，通常被认为是一个单一物种。这些谱系包括无性谱系、能够自花受精的谱系和只能异花受精的谱系。还代表了七个已知的交配种群，群体的隔离，可以潜在地杂交，其中每一个可能代表一个不同的进化谱系。这种多样性包括已知引起植物和动物多种疾病的分离物群。在这个项目中，将收集和分析来自四个不同核基因的DNA序列，以确定基于共享突变的进化谱系，并将如此识别的谱系与交配相容性和形态独特性定义的群体进行比较。在亚洲和南美洲与外国同事的实地工作将提供新的收藏，以增加培养和实验室股票保持在镰刀菌股票中心博士。这项工作的结果将是一个详细的系统发育树为这个物种的复杂，它可以用来找到分类学上可靠的字符，并预测生物学上有趣的特性，如无性和致病性的可能性在不同的主机。

0089474Geiser Fungi in the genus Fusarium are extremely important as agents of disease in plants and animals, as producers of toxins that poison food and animal feeds, as creative producers of chemicals with potential pharmaceutical uses, and even as food for human consumption. Despite their importance, identifying fusaria is very difficult, because they offer relatively few morphological characters that are useful for discrimination. This has led to a taxonomic system where extremely diverse sets of evolutionarily distinct lineages (judged on the basis of their inability to mate and form spores) are lumped together. This project by Dr. David Geiser at Pennsylvania State University and his USDA colleague Dr. Gary Samuels focuses on the Fusarium solani species complex, a cosmopolitan group of approximately 50 diverse evolutionary lineages that has most often been considered a single species. These lineages include asexual lineages, lineages that are capable of self-fertilization, and lineages that can only cross-fertilize. Also represented are seven known mating populations, groups of isolates that can potentially interbreed, each of which may represent a distinct evolutionary lineage. This diversity includes groups of isolates that are known to cause a wide variety of diseases of plants and animals. In this project, DNA sequences from four different nuclear genes will be gathered and analyzed, to identify evolutionary lineages based on shared mutations, and the lineages so recognized will be compared with the groups defined by mating compatibility and morphological distinctness. Field work in Asia and South America with foreign colleagues will provide new collections to augment the cultures and laboratory stocks maintained at the Fusarium Stock Center by Dr. Geiser. The result of the work will be a detailed phylogenetic tree for this species complex, which can be used to find taxonomically reliable characters and to predict the likelihood of biologically interesting traits such as asexuality and pathogenicity on different hosts.