PRF/J: Intraspecific Chloroplast-DNA Variation and Phytogeography in the Pacific Northwest

PRF/J：太平洋西北地区种内叶绿体 DNA 变异和植物地理学

• 批准号: 9303299
• 负责人: Jacqueline Soule
• 金额: --
• 依托单位: Individual Award
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9303299&HistoricalAwards=false
• 关键词: PRF; Intraspecific; Chloroplast; DNA; Variation

Many plants exhibit a similar geographic distribution, occurring from southeastern Alaska to northern California. Molecular genetic investigations of three species have revealed a pronounced north-south cytoplasmic discontinuity located south of the Wisconsin glacial maximum. These data implicate glaciation as a possible causal factor in creating the discontinuity and raises the possibility of a link between phytogeography and the genetic architecture of plants in the Pacific Northwest. If so, then other plants displaying similar geographic distributions should also exhibit similar patterns of genetic variation. This study addresses two questions: (a) do similar geographic patterns of chloroplast DNA (cpDNA) variation occur throughout a spectrum of Pacific Northwest plant taxa?, (b) are patterns of variation in cytoplasmic and nuclear markers congruent? Populations of five taxonomically diverse taxa (a gymnosperm, a monocot, and dicots from Dilleniidae, Rosidae, and Asteridae) having different life history features will be examined using cpDNA restriction site analysis, rDNA analysis, and enzyme electrophoresis. From these data, phylogenies will be generated and patterns of genetic variation will be assessed. Further analysis will address biogeographical questions and may help clarify the location and extent of suspected glacial refugia. %%% Our knowledge of the extent of intraspecific cpDNA variation will be enhanced through this investigation. It will also serve to facilitate a broad comparison of patterns and extent of cpDNA variation within species to that observed for nuclear genetic markers, improve knowledge of plant genetic architecture, and establish an important link between the areas of systematics and population genetics.

许多植物表现出类似的地理分布，分布在从阿拉斯加东南部到加利福尼亚北部的地区。 对三个物种的分子遗传学研究揭示了位于威斯康星州冰川极大期以南的明显的南北细胞质不连续性。 这些数据表明冰川作用可能是造成不连续性的原因，并提出了太平洋西北地区植物地理学与植物遗传结构之间存在联系的可能性。 如果是这样，那么具有相似地理分布的其他植物也应该表现出相似的遗传变异模式。 本研究解决了两个问题：(a) 叶绿体 DNA (cpDNA) 变异的相似地理模式是否存在于整个太平洋西北植物分类群中？(b) 细胞质和核标记的变异模式是否一致？ 将使用 cpDNA 限制性位点分析、rDNA 分析和酶电泳来检查具有不同生活史特征的五种分类学上不同的类群（裸子植物、单子叶植物和来自 Dilleniidae、Rosidae 和 Asteridae 的双子叶植物）的种群。 根据这些数据，将生成系统发育并评估遗传变异的模式。 进一步的分析将解决生物地理问题，并可能有助于澄清疑似冰川保护区的位置和范围。 %%% 通过这次调查，我们对种内 cpDNA 变异程度的了解将得到加强。 它还将有助于促进物种内 cpDNA 变异的模式和程度与核遗传标记观察到的模式和程度的广泛比较，提高对植物遗传结构的了解，并在系统学和群体遗传学领域之间建立重要联系。