Comparison of genetic diversity and ecophysiological performance in the colony-forming polar prymnesiophyte species Phaeocystis antarctica and Phaeocystis pouchetii

prymnesiophyte Phaeocystis是一种世界性的、具有重要生态意义和形成水华的浮游植物属，包含两个形成殖民地的冷水物种：北极的P. pouchetii和南大洋的P. antarctica。核糖体RNA （rRNA）和ITS （Internal转录间隔）序列的初步分子生物学分析表明，P. pouchetii具有丰富的种间和种内多样性，可能存在物种复合体，并试图追踪南极沿海水域P. antarctica菌株的生物地理历史。基于这些结果，对这两个极地物种的种群结构进行详细分析，旨在将遗传数据与环境参数以及生态生理反应模式联系起来。微卫星，短的，重复的序列，高度多态性，南极南极的设计和成功应用，但仍在等待统计分析。我们现在将能够研究来自不同地区的种群内部的遗传多样性以及它们之间的基因流动。同样的方法也计划用于P. pouchetii——尽管如果为P. antarctica设计的标记物的适用性测试失败，还需要开发微型卫星。选择遗传差异较大的两种褐囊藻克隆，对其在不同非生物条件下的光合作用和生长进行比较研究，勾勒出各自的最优和耐受极限。主要目的是通过实验评估遗传差异是否反映在不同的生态生理反应模式中，从而很好地解释特定的生物地理分布模式。此外，这种新方法首次提供了将人口遗传学与两极地区预测的气候变化联系起来的机会。

The prymnesiophyte Phaeocystis is a cosmopolitan, ecologically important and bloom-forming genus of the phytoplankton containing two colony-forming cold water species: P. pouchetii in the Arctic and P. antarctica in the Southern Ocean. Preliminary molecular biological analyses of the ribosomal RNA (rRNA) and ITS (Internal Transcribed Spacer) sequences indicated substantial inter- and intraspecific diversity, the possibility of a species complex in P. pouchetii and tried to trace the biogeographic history of P. antarctica strains in Antarctic coastal waters. Based on these results, a detailed analysis of the population structure of both polar species is intended to link genetic data to environmental para-meters as well as to ecophysiological response patterns. Microsatellites, short, repetitive sequences that are highly polymorphic, for P. antarctica were designed and successfully applied but still await statistical analysis. We will now be able to study the genetic diversity inside populations from different locations and the gene flow between them. The same approach is also planned for P. pouchetii al-though microsatellites have still to be developed if applicability tests with markers designed for P. antarctica fail.Selected clones of both Phaeocystis species with large genetic differences will be comparatively studied in terms of photosynthesis and growth under different abiotic conditions to outline the res-pective optima and tolerance limits. The main goal is to experimentally evaluate whether genetic differences are reflected in different ecophysiological response patterns which could well explain specific biogeographic distribution patterns. Moreover, this new approach offers for the first time the opportunity to relate population genetics to predicted climatic changes in both Polar Regions.