Lifetime Fitness of Hybrids in Natural Plant Populations: Testing Models for Hybrid Zones

自然植物种群中杂交品种的终生适应性：杂交区模型测试

• 批准号: 9806547
• 负责人: Diane Campbell
• 金额: $ 20万
• 依托单位: Rocky Mountain Biological Laboratory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806547&HistoricalAwards=false
• 关键词: Lifetime; Fitness; Hybrids; Natural; Plant

Campbell 9806547 Hybrid zones are areas where related species, or other genetically distinct populations, come together and produce some viable offspring. Hybridization is particularly widespread in flowering plants and also occurs in many animal groups. Evolutionary biologists propose several models to explain patterns of genetic variation across the resulting hybrid zones. These models differ in the assumptions they make about natural selection on hybrids, and they have different important consequences for long-term evolution. Understanding the processes responsible for maintaining hybrid zones can also be applied to prevention of hybridization between crops and related weeds, and to conservation of rare species that occur near more common relatives. This study will test models for hybrid zones by comparing the lifetime fitness of parent and hybrid plants in the field. The investigators will follow the survival and final reproductive success of offspring generated from experimental crosses between two closely related species, Ipomopsis aggregata and Ipomopsis tenuituba, and planted as seeds into several locations. First generation and second generation hybrids will be planted. Each model can be distinguished by its unique predictions about the fitnesses of hybrids and parental individuals and how these change across environments. In addition, the investigators will determine whether interactions between pollen grains of the two species can reduce the level of hybrid formation and contribute to geographical variation in the extent of hybridization. This goal will be met using experiments and computer simulations to determine the mixtures of pollen that reach flowers in natural populations, and by performing experimental pollinations and genetic analysis of seeds.

Campbell 9806547 杂交区是相关物种或其他遗传上不同的种群聚集在一起并产生一些可存活后代的区域。杂交在开花植物中尤其普遍，并且也发生在许多动物群体中。 进化生物学家提出了几种模型来解释由此产生的杂交区域的遗传变异模式。 这些模型对杂种自然选择的假设有所不同，并且对长期进化有不同的重要影响。 了解负责维持杂交区的过程也可以应用于防止作物和相关杂草之间的杂交，以及保护在更常见的亲戚附近出现的稀有物种。 这项研究将通过比较田间亲本植物和杂交植物的生命周期适应性来测试杂交区模型。 研究人员将跟踪两个密切相关的物种（Ipomopsis aggregata 和 Ipomopsis tenuituba）之间的实验杂交产生的后代的存活和最终繁殖成功率，并将其作为种子种植到多个地点。 将种植第一代和第二代杂交品种。每个模型都可以通过其对混合体和亲本个体的适应性以及它们如何随环境变化的独特预测来区分。 此外，研究人员还将确定两个物种的花粉粒之间的相互作用是否会降低杂交形成的水平并导致杂交程度的地理差异。这一目标将通过实验和计算机模拟来确定自然群体中到达花朵的花粉混合物，并通过进行实验授粉和种子遗传分析来实现。

项目成果

Early snowmelt projected to cause population decline in a subalpine plant

• DOI: 10.1073/pnas.1820096116
• 发表时间: 2019-06-25
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Campbell, Diane R.