SGER: Gene Flow and Hybridization Between Introduced and Endemic Populations of Three Native Perennial Grass Species

种群生物学的一个基本问题是确定新基因在自然种群中的传播程度及其对进化和生态过程的影响。 在植物方面，由于种子的意外传播和恢复原生植被的努力，将新的遗传物质引入土著种群变得越来越普遍。 虽然引入新的遗传物质可能会使遗传多样性很少的人群受益，但也存在严重的潜在风险。 例如，当代表遗传上不同的种群的个体交配和杂交时，通过有性生殖将两个种群的遗传物质混合，可能导致杂交后代（或两代后的后代）对当地生态条件的适应性很差。 这种现象被称为“杂交崩溃”，并可能导致灭绝的风险增加。 到目前为止，主要的恢复工作可能会为后代带来这样一个“毒丸”（即，杂交分解）才刚刚开始被生态学家讨论。 将在这里启动的合作将是对草原物种这种可能性的首次研究，草原物种一直是恢复工作的主要重点。 研究人员将使用分子指纹技术，以寻求证据的杂交和杂种之间的引进和本地加州多年生禾本科植物在一个广泛的草原/橡树林地保护区由加州大学管理的居民人口的崩溃。

0081024Mazer and ReichmanA fundamental problem in population biology is determining the extent of the spread of novel genes in natural populations and its effect on evolutionary and ecological processes. In plants, the introduction of novel genetic material into indigenous populations is becoming more common due to the accidental spread of seeds and due to attempts to restore native vegetation. While the introduction of new genetic material may benefit populations with little genetic diversity, there are also serious potential risks. For example, when individuals representing genetically distinct populations mate and hybridize, the mixing of the genetic material from the two populations through sexual reproduction can result in hybrid offspring (or grandoffspring, two generations later) that are poorly adapted to local ecological conditions. This phenomenon is known as "hybrid breakdown" and can result in an increased risk of extinction. To date, the possibility that major restoration efforts may hold such a "poison pill" for future generations (i.e., hybrid breakdown) has just begun to be discussed by ecologists. The collaboration to be initiated here will be the first study of this possibility in grassland species, which have been a major focus of restoration efforts. The investigators will use molecular fingerprinting techniques to seek evidence for hybridization and hybrid breakdown between introduced and resident populations of three species of native California perennial grasses at an extensive grassland/oak woodland reserve managed by the University of California.