Studies of Costa Rican Gelidiales (Rhodophyta): four Caribbean taxa including Pterocladiella beachii sp. nov.
Studies of Costa Rican Gelidiales (Rhodophyta): four Caribbean taxa including Pterocladiella beachii sp. nov.
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DOI：
10.2216/i0031-8884-40-4-340.1
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发表时间：
2001-07
期刊：
影响因子：
1.6
通讯作者：
D. T. Thomas;D. W. Freshwater
中科院分区：
文献类型：
--
作者：
D. T. Thomas;D. W. Freshwater
摘要 此前已在哥斯达黎加加勒比海岸记录到红藻目 Gelidiales 中的八种物种。在本研究中，使用 rbcL 和 LSU 基因序列数据的形态学观察和分析来确定四种加勒比物种的身份和系统发育关系：Gelidium microdonticum、G. floridanum、Pterocladiella bartettii 和 P. beachii Freshwater sp。十一月以前从哥斯达黎加收集的小型石花菜属物种被称为 G. microdonticum 或太平洋物种 G. microdentatum。对这些以前的收藏品以及为本研究收集的收藏品的观察证实它们都是 G. microdonticum。分子分析表明，该物种与主要来自南非和南大西洋的一组物种有亲缘关系。我们还提供了来自哥斯达黎加的 G. floridanum 的首次报告。序列分歧值表明哥斯达黎加 G. floridanum 与来自东加勒比和西大西洋的种群之间存在遗传不连续性。囊果发育特征以及分子分析结果清楚地确定了新种 P. beachii 属于 Pterocladiella。形态学和分子结果也表明该物种与 P. caerulescens 密切相关。 Pterocladiella beachii 在 Pterocladiella 物种中可能是独一无二的，因为它具有中央胎盘核心，该核心位于囊果发育所有阶段的中心。
Abstract Eight species within the red algal order Gelidiales have previously been recorded from the Caribbean coast of Costa Rica. In this study morphological observations and analyses of rbcL and LSU gene sequence data were used to determine the identity and phylogenetic relationships of four Caribbean species: Gelidium microdonticum, G. floridanum, Pterocladiella bartlettii and P. beachii Freshwater sp. nov. Previous collections of a small Gelidium species from Costa Rica have been referred to either G. microdonticum or the Pacific species, G. microdentatum. Observations of these previous collections, as well as collections made for this study, verify that they are all G. microdonticum. Molecular analyses show that this species has an affinity with a group of species predominantly from South Africa and the south Atlantic. We also provide the first report of G. floridanum from Costa Rica. Sequence divergence values suggest a genetic discontinuity between Costa Rican G. floridanum and populations from the east Caribbean and western Atlantic. Characteristics of cystocarp development, as well as the results of molecular analyses, clearly identify the new species P. beachii as belonging to Pterocladiella. Morphological and molecular results also indicate that this species is closely related to P. caerulescens. Pterocladiella beachii may be unique among Pterocladiella species in having a central placental core that is centrally positioned throughout all stages of cystocarp development.