PRF/M: Parasites and Herbivores as Agents of Natural Selection in Plants

PRF/M：寄生虫和食草动物作为植物自然选择的媒介

• 批准号: 9004287
• 负责人: Yan Linhart
• 金额: $ 6.45万
• 依托单位: Fellowships
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1991-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9004287&HistoricalAwards=false
• 关键词: PRF; Parasites; Herbivores; Agents; Natural

Disease-producing and parasitic species are important agents of natural selection in the evolution of their hosts. Disease-producing species are often bacteria or fungi; parasites are often insects or other invertebrates. Each of these classes of organisms has a different physiology, and therefore can present a different challenge to a host. Ford and Haldane postulated that this diversity of challenges produces a diversity of selective pressures which help explain the high genetic diversity observed in human populations. The PI plans to test the generality of this hypothesis by using a woody perennial plant, the wild thyme (Thymus vulgaris L.) and three species that parasitize it or feed upon it. These include the mollusk Agriolimax reticulatus Muller, the lepidopteran Pyrausta sanguinalis L., and the mildew fungus Oidium sp. Thyme plants can be characterized by their terpene composition, and single plants contain a single terpene. The biochemical pathways of terpene production are known, and the genetic control of terpene production involves single Mendelian loci. Thyme populations are highly polymorphic for these terpene chemotypes. The PI proposes to (1) study the differential sensitivity of these terpene variants to parasites and (2) document the diversity of selective pressures generated.

致病物种和寄生物种是宿主进化过程中自然选择的重要媒介。 致病物种通常是细菌或真菌；寄生虫通常是昆虫或其他无脊椎动物。 每一类生物体都有不同的生理机能，因此会给宿主带来不同的挑战。 福特和霍尔丹假设，这种多样性的挑战产生了多样性的选择压力，这有助于解释在人类群体中观察到的高度遗传多样性。 PI 计划通过使用一种多年生木本植物、野生百里香 (Thymus vulgaris L.) 和三种寄生于它或以它为食的物种来测试这一假设的普遍性。 这些包括软体动物 Agriolimax reticulatus Muller、鳞翅目 Pyrausta sanguinalis L. 和霉菌真菌 Oidium sp。 百里香植物的特征在于其萜烯成分，并且单个植物含有单一萜烯。 萜烯生产的生化途径是已知的，并且萜烯生产的遗传控制涉及单个孟德尔基因座。 百里香群体对于这些萜烯化学型具有高度多态性。 PI 建议 (1) 研究这些萜烯变体对寄生虫的不同敏感性，以及 (2) 记录产生的选择压力的多样性。