Phylogenetics of Epichloe Species and Related Grass Mycosymbionts

附生植物物种和相关草真菌共生体的系统发育

• 批准号: 9408018
• 负责人: Christopher Schardl
• 金额: $ 16.47万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1997-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9408018&HistoricalAwards=false
• 关键词: Phylogenetics; Epichloe; Species; Related; Grass

9408018 Schardl Drs. Schardl and Siegel at the University of Kentucky in collaboration with Swiss colleagues are studying a fascinating group of ascomycetous fungi that invade or infect grasses and sedges, fungi usually treated in the genus Epichloe. The grasses infected include commercially important turf grasses. The taxonomy and classification of the fungi is complicated by the occurrence of asexual forms and by a general paucity of reliable morphological characters for distinguishing species. Yet Epichloe strains are known to inhabit grass plants internally, where they may function either as mutualists or as pathogens. The mutualistic endophyte fungi are transmitted through the hosts' seeds and they provide protection from insect herbivores and drought. The pathogenic Epichloe inhibit seed production by the host and are able to produce infecting spores in large quantities. The investigators are studying patterns and mechanisms of fungal speciation, mating systems, and hybridization, while also seeking to determine whether the fungi coevolve with their grass hosts. Primary objectives are (1) to use DNA sequence analysis as a tool for determining phylogenetic relationships of Epichloe species and relatives, both teleomorph and anamorph taxa; (2) to determine the number and pattern of origins of mutualism and pathogenicity in these fungi; and (3) to correlate these patterns with the known phylogeny of the grass hosts. The possibility of hybridization between Epichloe strains leading to the formation of asexual "species" will also be examined.

小行星9408018 肯塔基州大学的Schardl博士和Siegel博士与瑞士同事合作，正在研究一组迷人的子囊菌真菌，它们侵入或感染草和莎草，真菌通常在Epichelus属中治疗。 受感染的草包括商业上重要的草坪草。 真菌的分类和分类由于无性形式的出现和普遍缺乏用于区分物种的可靠形态特征而变得复杂。 然而，已知Epichelium菌株栖息在禾本科植物内部，在那里它们可能作为互利者或病原体发挥作用。 共生内生真菌通过宿主的种子传播，它们提供保护，免受食草昆虫和干旱的侵害。 致病性Epichelium抑制宿主的种子生产，并能够产生大量的感染孢子。 研究人员正在研究真菌物种形成，交配系统和杂交的模式和机制，同时也试图确定真菌是否与其草宿主共同进化。 主要目的是（1）使用DNA序列分析作为确定Epichelium物种和亲缘关系的工具，包括有性型和无性型分类群;（2）确定这些真菌中互利共生和致病性起源的数量和模式;（3）将这些模式与已知的禾本科宿主的系统发育相关联。 还将研究Epichelium菌株之间杂交导致无性“种”形成的可能性。