Morphological and Molecular Investigations on the Orthotricheae (Orthotrichaceae: Bryopsida)

肖DEB 9806955 在陆生植物中，寄生植物占据着关键的地位，因为它们是唯一的陆生植物，其中生活史的单倍体配子体阶段而不是二倍体孢子体阶段占主导地位，并且因为它们的生殖系统依赖于水来将精子移动到卵子。 在这种情况下，它们可以被认为是“植物中的两栖动物”，标志着水生生物和完全陆生生物之间的过渡。 苔藓是迄今为止最大的苔藓类，约有12，000种。 苔藓的结构特征，包括染色体数目的演变，是知之甚少，尽管重要的brabrites植物多样性的一般理解。 本计画将探讨藓类大科木藓科中物种间的亲缘关系。 木藓科在各大洲都有分布，是热带和温带生态系统的不同组成部分。 这项研究将把对DNA水平变异的联合收割机分子分析与生殖生物学、染色体数目和结构以及整株植物的比较解剖学研究结合起来。 这些综合分析的结果将为生殖生物学和染色体数量变化等生物学特征与通过近亲和远亲物种之间DNA结构差异估计的分子多样化率之间的关系提供新的线索。

Shaw DEB 9806955 Byophytes occupy a pivotal position among land plants because they are the only land plants in which the haploid gametophyte stage rather than the diploid sporophyte stage of the life cycle is dominant and because their reproductive system relies on water for movement of sperm to eggs. In that context, they can be thought of as the "amphibia of plants," marking the transition between aquatic and completely terrestrial organisms. The mosses are by far the largest groups of bryophytes, with some 12,000 species. The evolution of moss structural characteristics, including chromosome number, is poorly understood despite the importance of bryophytes for a general understanding of plant diversity. This project will investigate the relationships among species in the large moss family Orthotrichaceae. The Orthotrichaceae are represented on every continent, and are diverse components of both tropical and temperate ecosystems. This research will combine molecular analyses of variation at the DNA level with studies of reproductive biology, chromosome numbers and structure, and comparative anatomy of whole plants. Results of these combined analyses will shed new light on the relationship between biological characteristics such as reproductive biology and changes in chromosome number, and rates of molecular diversification as estimated by differences in DNA structure among closely related and more distantly related species.