Molecular and Morphological Studies of Evolution in the Gelidiales (Rhodophyta)

9726170淡水红藻目石斑藻含有许多重要的经济物种；石斑藻是琼脂的主要来源，广泛用于食品和化妆品工业以及微生物学、生化和遗传学研究。然而，这个群体作为一个整体，以及其中的物种，一直很难识别和分类。传统的红藻分类，包括Gelidies红藻，一直基于特定的生活史类型和雌性生殖系统发育形态的特征。雌性生殖系统的发育特征和生活史中的相关阶段被认为对红藻的分类是有用的，因为这些特征的变化将防止改变的和未改变的藻类种群之间的杂交繁殖(生殖隔离)，从而导致物种的形成，并最终形成物种的谱系(支系)。需要独立的数据来测试这些生殖特征在分类中有用的想法，也需要提供一种方法来对藻类进行分类，因为在许多Gelidiae中，很难从生殖系统获得或解释信息。在这项研究中，D.Wilson Freshwater将记录关键的盖氏分类群的营养形态和繁殖策略，并将根据这些特征和来自几个核和叶绿体基因的DNA序列数据重建这些分类群的系统发育历史。预计这项工作将有力地重建Gelidies的系统发育历史，并评估生活史和生殖特征在重建这一历史、Gelidies和其他红藻中的作用。

9726170 Freshwater The red algal order Gelidiales contains many economically important species; gelidialean algae are a principal source of agar, widely used in the food and cosmetics industry and in microbiological, biochemical and genetics research. However, the group as a whole, and species within it, have been difficult to identify and classify. Traditional classifications of red algae, including the Gelidiales, have been based on particular life history types, and characteristics of the developmental morphology of the female reproductive system. Developmental characteristics of the female reproductive system and related stages in the life history are thought to be useful in classifications of red algae, because changes in these characters would prevent cross-breeding between changed and unchanged algal populations (reproductive isolation), leading to the formation of species and, ultimately, lineages of species (clades). Independent data are needed to test the idea that these reproductive characters are useful in classification, and also are needed to provide a means of classifying algae for which, as in many Gelidiales, information from reproductive systems is hard to obtain or interpret. In this study, D. Wilson Freshwater will document the vegetative morphology and reproductive strategies of key gelidialean taxa, and will reconstruct the phylogenetic history of these taxa on the basis of both these characters and DNA sequence data from several nuclear and plastid genes. The work is expected to result in a robust reconstruction of the phylogenetic history of the Gelidiales and evaluate the utility of life history and reproductive characters in reconstructing this history, in Gelidiales and in other red algae.