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

[212719]霍奇：很少有研究对用于昆虫生物防治计划的真菌的种类限制进行测试。其中一组子囊真菌是Hypocrella和Aschersonia组，前者具有有性子囊孢子产生阶段，后者只有或通常无性孢子形成阶段，但最近的DNA序列数据显示可能是各种有性的Hypocrella物种的近亲。这些真菌主要感染同翅目昆虫，通常是蚧虫和白蝇，在20世纪初，一些真菌被用来控制佛罗里达州柑橘林的害虫。物种之间的分类学界限以及有性和无性形式之间的联系仍然缺乏研究，这反过来又限制了改进生物防治剂的发展。康奈尔大学的凯西·霍奇博士将与研究生们一起分析关键的阿氏阿氏线虫和古黛娜阿氏线虫的物种关系，重点是整合形态学、交配试验和多基因序列的数据，建立反映生物体生物学特性的物种界限，同时为从可观察到的表型特征中快速识别提供实用工具。分类数据将从现有的植物标本馆标本和实验室培养物，以及在佛罗里达州和其他地方实地工作中新收集的材料中收集，并辅以世界各地同事提供的材料。将产生新的分类识别资源和密钥。进化关系将通过形态特征的系统发育分析和从几个核糖体和蛋白质编码基因获得的DNA序列数据进行评估。研究生将接受收集技术和现代系统发育系统学方面的培训。将产生出版物和基于互联网的资源，以将工作结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.