Hypocrella and Aschersonia: Systematics and Evolution in the Clavicipitaceae (Ascomycota)

对昆虫生物防治项目中使用的真菌的物种限制进行的研究很少。其中一个子囊菌群是下甲菌群和无菌菌群，前者有有性、子囊产生期，后者只有或通常有无性孢子形成期，但最近的DNA序列数据表明，它们很可能是各种有性下甲菌的近亲。这些真菌主要感染同翅目昆虫，通常是介壳虫和粉虱，一些真菌早在20世纪初就被用来控制佛罗里达州柑橘园的害虫。物种之间的分类界限以及有性和无性形式之间的联系仍然研究得很少，这反过来又限制了改进的生防剂的发展。康奈尔大学的Kathie Hodge博士将与那里的研究生合作，分析关键的Aschersonia aleyrodis和A.Goldiana复合体中的物种关系，重点是整合来自形态学、交配试验和多基因序列的数据，以建立反映生物生物学特性的物种界限，同时提供实用工具，从可观察的表型特征中快速识别。分类学数据将从现有的标本馆标本和实验室培养中收集，并从佛罗里达州和其他地方实地工作期间新收集的材料中收集，再加上世界各地同事提供的材料。将生成新的分类标识资源和关键字。将通过对形态特征和从几个核糖体和蛋白质编码基因获得的DNA序列数据进行系统发育分析来评估进化关系。一名研究生将接受收集技术和现代系统发生学方面的培训。将出版出版物和互联网资源，将工作成果传递给其他生物学家和公众。

0212719Hodge Few studies have been conducted to test species limits in fungi used in insect biocontrol programs. One such group of ascomycete fungi is the Hypocrella and Aschersonia group, the former with sexual, ascospore producing phases and the latter with only or usually asexual spore forming phases, but shown with recent DNA sequence data to be likely close relatives of various sexual Hypocrella species. These fungi mostly infect Homoptera insects, usually scale insects and whiteflies, and some were used early in the 1900s to control pests of citrus groves in Florida. The taxonomic boundaries between species and the linkages between sexual and asexual forms remain poorly studied, which in turn has limited the development of improved biocontrol agents. Dr. Kathie Hodge of Cornell University will work with graduate students there to analyze species relationships in the critical Aschersonia aleyrodis and A. goldiana complex, with a focus on integrating data from morphology, mating trials, and multi-gene sequences to establish species circumscriptions that reflect biological properties of the organisms while providing practical tools for rapid identification from observable phenotypic features. Taxonomic data will be gathered from existing herbarium specimens and laboratory cultures, and from material newly collected during field work in Florida and elsewhere, augmented with material provided by colleagues around the world. New taxonomic identification resources and keys will be generated. Evolutionary relationships will be assessed through phylogenetic analyses of morphological characters and of DNA sequence data obtained from several nuclear ribosomal and protein-coding genes. A graduate student will be trained in collecting techniques and in modern phylogenetic systematics. Publications and Internet-based resources will be generated to transmit the results of the work to other biologists and to the public.