Host Specialization and Fungal Speciation in Ceratocystis

Ceratocystis 的宿主特化和真菌物种形成

• 批准号: 0128104
• 负责人: Thomas Harrington
• 金额: $ 30万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-15 至 2005-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0128104&HistoricalAwards=false
• 关键词: Host; Specialization; Fungal; Speciation; Ceratocystis

0128104Harrington Studies of fungal species, their reproductive strategies, how they evolve, and how humans influence their evolution and distribution are needed. This need is particularly acute for plant pathogenic fungi because humans unwittingly move cryptic species of fungi around the world on their crops (mostly on plant propagative materials such as seeds and cuttings) and plant products (such as logs, wood chips, packing materials, etc.), often with devastating consequences. Introductions of invasive fungal species and changes in fungal populations frequently frustrate disease control strategies, reduce food and fiber productivity, and threaten forest ecosystems. Ceratocystis species, which are primarily found in the Americas, have been particularly damaging when introduced into new ecosystems or when introduced plant hosts come into contact with indigenous pathogen populations. The research of Dr. Thomas Harrington at Iowa State University focuses on how new species arise in the Ceratocystis fimbriata complex, which contains some of the most aggressive pathogens in the genus Ceratocystis. Although currently considered one species, it is actually a complex of many species that share morphological similarities but infect different hosts in different parts of the world. Dr. Harrington will use a variety of modern molecular and traditional tools to delimit species within the complex and infer their evolutionary history. Particular emphasis will be given to the host range (which hosts the pathogen can infect) of each of the delimited species. DNA fingerprinting markers will be used to study the diversity of populations and trace the suspected spread of host-specialized species by human activity. Recently derived populations should have low levels of genetic diversity and have limited geographic ranges, except where the geographic range has been extended by humans. Older lineages are hypothesized to have more genetic diversity and broader geographic ranges. Also, the hypothesis that older lineages are more restricted in their host ranges will be tested. These studies will build a foundation for a taxonomic treatment of this ecologically and economically important genus. Where and how populations of C. fimbriata were introduced by humans will also be determined, and this information will be particularly important because of the increasing movement of plant pathogens on logs, wood chips and crating material. The studies will allow for a better understanding of how ecological niche affects speciation and will lead to a more practical definition of species in the fungi. The definition of a species continues to be among the most controversial issues in basic biology, but the practical implications for plant pathology, particularly for quarantine concerns, are immediate. Concerns over invasive species, including plant pathogens, have been heightened by the globalization of our economies, and the simple concept of a species continues to be of pivotal importance to the prevention of introductions and management of introduced pests.

0128104哈灵顿 需要研究真菌物种，它们的繁殖策略，它们如何进化，以及人类如何影响它们的进化和分布。 这种需求对于植物病原真菌来说特别迫切，因为人类无意中将真菌的隐蔽物种在世界各地移动到他们的作物（主要是植物繁殖材料，如种子和插条）和植物产品（如原木、木屑、包装材料等）上，往往带来毁灭性的后果。 入侵真菌物种的引入和真菌种群的变化经常阻碍疾病控制策略，降低粮食和纤维生产力，并威胁森林生态系统。 主要在美洲发现的Ceratocystis物种在引入新的生态系统或引入的植物宿主与土著病原体种群接触时特别具有破坏性。爱荷华州州立大学的托马斯哈灵顿博士的研究重点是新物种如何在长喙囊藻复合体中出现，该复合体包含长喙囊藻属中一些最具侵略性的病原体。 虽然目前被认为是一个物种，但它实际上是许多物种的复合体，这些物种具有形态相似性，但感染世界不同地区的不同宿主。 哈灵顿博士将使用各种现代分子和传统工具来界定复杂物种并推断其进化历史。 将特别强调每个划定物种的宿主范围（病原体可以感染的宿主）。 DNA指纹标记将用于研究种群的多样性，并追踪人类活动引起的宿主特有物种的可疑扩散。 最近衍生的种群应具有低水平的遗传多样性，并具有有限的地理范围，除非地理范围已被人类扩展。 较老的谱系被假设具有更多的遗传多样性和更广泛的地理范围。 此外，假设较老的血统更受限制，在其主机范围将进行测试。 这些研究将为该属植物的分类学研究奠定基础。 C.此外，还将确定人类引入的菌毛植物病原体的数量，这一信息将特别重要，因为植物病原体在原木、木屑和板条箱材料上的移动越来越多。 这些研究将有助于更好地了解生态位如何影响物种形成，并将导致真菌中物种的更实际定义。物种的定义仍然是基础生物学中最有争议的问题之一，但对植物病理学的实际影响，特别是检疫问题，是直接的。 我们经济的全球化加剧了对包括植物病原体在内的入侵物种的关切，物种的简单概念对于防止引进和管理引进的害虫仍然至关重要。