A Morphological and Molecular Investigation of Castaneoid Evolution

[707945]马诺斯：在生态和经济上都很重要的壳子科，由橡树、山毛榉和栗子组成，温带植物学家最熟悉的是相对较少的几种。但是这个科有许多热带物种，在东南亚尤其多样化，杜克大学的保罗·马诺斯博士将在那里进行实地考察，对两个最大的属Castanopsis和Lithocarpus进行取样。这两个属占该科物种多样性的近一半，并且在特征对偶（毛刺或橡子）中表现出比该科温带成员更大的形态多样性。该研究的一个目标是通过将这些植物的传统形态学知识与核糖体基因DNA测序的新分子数据相结合，推断许多热带物种之间的谱系或系统发育关系，这些数据提供了样本之间突变差异的直接测量。这种系统发育框架反过来将允许分析热带和亚热带壳斗科谱系中各种羽对形态的发展史，特别是在成熟时难以区分但怀疑从不同幼年阶段趋同进化的羽对类型。“热带栗子”或castanoid的物种多样化的范围和历史鲜为人知。野外工作、现有植物标本的研究和新的DNA序列数据将结合在一起，以提高我们对这些植物的基本分类和系统发育的认识。热带多样性通常包含理解温带植物进化史的关键要素，这可能是东南亚多样化，昆虫授粉的Castanopsis和Lithocarpus的情况。这些研究将证明对解释形态进化是有用的，并将把castanoid的主要类群置于地理和系统发育框架中。

9707945 Manos The ecologically and economically important family Fagaceae of oaks, beeches, and chestnuts is most familiar to temperate-zone botanists from a relative handful of species. But the family has many tropical species, and is especially diverse in southeast Asia, where Dr. Paul Manos of Duke University will be conducting field work to sample the two largest genera, Castanopsis and Lithocarpus. These two genera comprise nearly half of the species diversity in the family and represent an even greater range of morphological diversity in the characteristic cupule (the burr or acorn) than found in the temperate-zone members of the family. One goal of the research is to infer genealogical or phylogenetic relationships among the many tropical species, by integrating traditional morphological knowledge of these plants with new molecular data from DNA sequencing of nuclear ribosomal genes, which provide a direct measure of mutational differences between samples. This phylogenetic framework in turn will allow analysis of the history of development of various cupule morphologies in the lineages of tropical and subtropical Fagaceae, especially among cupule types that are indistinguishable at maturity but suspected of convergent evolution from different juvenile stages. The range and history of species diversification in the "tropical chestnuts" or castaneoids are poorly known. Field work, study of existing herbarium collections, and new DNA sequence data will be brought together to improve our understanding of the basic taxonomy and phylogeny of these plants. Tropical diversity often contains key elements to understand the evolutionary history of plants in the temperate zone, and this is likely to be the case with the diverse, insect-pollinated Castanopsis and Lithocarpus of southeast Asia. The studies will prove useful in interpreting morphological evolution, and will place the major groups of castaneoids into a geographical as well as phylogenetic framework.