CRB: Evolutionary and Conservation Genetics of Native Hawaiian Ferns

夏威夷群岛拥有世界上最独特的植物群之一。由于其丰富的生物多样性和极端的地理隔离，夏威夷群岛经常被誉为研究有机进化模式和过程的理想地点。然而，由于人类和引进的动物改变了栖息地，以及外来杂草植物的入侵，夏威夷的许多独特植物濒临灭绝。特别是森林生境的破碎化可能减少能够在野外繁殖的成熟植物的有效数量。因此，迫切需要进行研究，不仅要解决进化问题，还要获得对明智地管理夏威夷植物资源有用的数据。在一个与夏威夷本土蕨类植物保护生物学相关的项目中，夏威夷大学的Thomas Ranker博士将使用酶电泳来描述24种夏威夷本土蕨类植物种群内部和种群之间的遗传多样性水平和模式。这些物种的微小配子体之间的异交和近交水平将通过检查蕨类孢子体的自然林分以及对选定的配子体的自然和实验室种群进行抽样来分析。对于特有属腺蝇属和沙蝇属的物种，配子体将在实验室培养，并测试影响生殖能力和异交行为的因素。将对分布广泛的常见物种和分布狭窄的稀有物种进行比较，并寻求遗传变异数量的相关性，以及这种变异在种群内或分散种群之间的分配。这些数据与维持夏威夷蕨类植物群遗传变异和整体多样性的有效种群大小的管理决策有关。

The Hawaiian Islands possess one of the most distinctive floras in the world. Because of its rich biodiversity and extreme geographic isolation, the Hawaiian archipelago is often praised as an ideal locality in which to study the patterns and processes of organic evolution. However, much of Hawaii's unique flora is endangered because of habitat conversion by humans and introduced animals and through the invasion of alien, weedy plant competitors. Fragmentation of forest habitat in particular may reduce the effective number of mature plants able to reproduce in the wild. There is a critical need, therefore, for studies which not only address evolutionary questions but also obtain data useful to the wise stewardship of Hawaii's plant resources. In a project relevant to the conservation biology of native Hawaiian ferns, Dr. Thomas Ranker of the University of Hawaii will employ enzyme electrophoresis to describe levels and patterns of genetic diversity within and among populations of 24 species of native Hawaiian ferns. Levels of outcrossing and inbreeding among the tiny gametophytes of these species will be analyzed by examining natural stands of fern sporophytes as well as by sampling natural and laboratory populations of selected gametophytes. For species of the endemic genera Adenophorus and Sadleria, gametophytes will be grown in the laboratory and tested for factors affecting reproductive capacity and outcrossing behavior. Comparisons will be made between wide-ranging, common species and narrowly distributed, rare ones, and correlations sought with amounts of genetic variation and apportionment of this variation within populations or among scattered populations. These data are pertinent to management decisions regarding effective population sizes for maintaining genetic variation and overall diversity in the Hawaiian fern flora.