Dissertation Research: Phylogeny and Speciation in Polygonella (Polygonaceae)

研究生保罗刘易斯，在博士的监督下。 俄亥俄州州立大学的丹·克劳福德将研究这种分类法 本文对云南黄精属11种植物的遗传多样性进行了研究。 美国东南部。 在本属中有几种 似乎已经进化为孤立的岛屿状种群 在更新世冰期之间的温暖时期， 冰川融化了 佛罗里达半岛被淹没在 这些时候，除了“岛屿”，代表了 最高的地块 两种黄精属植物 例如，仅限于威尔士湖山脊， 中心的佛罗里达半岛，和其他物种可能有 从这个地方病流行的地区分散开来。 该研究将审查 物种内部和物种之间的形态变异， 植物的遗传变异，通过测量酶的变化， 电泳 酶法检测基因性状 电泳可能会产生有用的数据，用于推断 物种之间的进化关系， 这些植物的育种系统方面，已知 在性别表达上可变。 因此，黄精属提供了一种 调查过去物种形成事件的不寻常机会 与更新世岛屿形成有关， 关于佛罗里达许多特有动植物的起源。

Graduate student Paul Lewis, under the supervision of Dr. Dan Crawford of Ohio State University, will study the taxonomy and genetic variability of 11 species of the genus Polygonella of the southeastern United States. In this genus several species appear to have evolved as isolated island-like populations during the warm periods between Pleistocene ice ages when glaciers melted. The Florida Peninsula was submerged during these times with the exception of "islands" that represented the highest land masses in the area. Two species of Polygonella for example are restricted to the Lake Wales ridge running down the center of the Florida peninsula, and other species may have dispersed from this endemic area. The study will examine morphological variability within and among the species and also genetic variation of plants by measuring enzyme variation using electrophoresis. Gene-characters detected by enzyme electrophoresis are likely to yield data useful for inferring evolutionary relationships among the species and for estimating aspects of breeding systems in these plants, which are known to be variable in sex expression. Thus Polygonella provides an unusual opportunity to investigate past speciation events associated with Pleistocene island formation which may shed light on the origin of many of Florida's endemic plants and animals.