DIVERSITY OF EUKARYOTIC ALGAE
DIVERSITY OF EUKARYOTIC ALGAE
复制标题
DOI：
10.1007/bf00693765
复制
发表时间：
1992-12-01
影响因子：
3.4
通讯作者：
ANDERSEN, RA
中科院分区：
文献类型：
--
作者：
ANDERSEN, RA
藻类无处不在。它们是所有海洋的主要生产者，海洋面积占地球表面的71%。藻类也出现在淡水湖、池塘和溪流中，以及土壤、岩石、冰、雪、植物和动物的表面和内部。总的来说，全球40%的光合作用是由藻类贡献的。在地质时期，至少有七种不同的系统发育谱系独立出现，并以不同的速度进化（基于分子钟）。因此，总的来说，藻类不会形成一个单一的、有凝聚力的群体，它们必须被认为是一个多系组合。红藻谱系大约有5000个公认的物种（不包括命名的同义词）。现存的多余的名字（等等），估计还有500到15000个新物种有待描述。绿藻谱系大约有16000种已知的现存物种，还有多达10万种有待描述。色生植物谱系大约有15000个已知的现存物种，还有100万到1000万个有待描述的物种。恐龙系（主要是鞭毛纲）大约有3000种已知的现存物种，工作人员估计还有500到8000种有待描述。裸藻谱系大约有900个已知的现存物种，专家估计还有1000个物种有待描述。隐生植物谱系正在经历全面修订，物种数量非常不确定；已知的现存物种大约有200种，还有1000种有待描述。蓝藻谱系有13个公认的物种，也许还有几十个物种有待描述。自20世纪60年代以来，在鉴定或描述新藻类之前，通常需要克隆培养然后进行电镜检查。最近，电子显微镜正在被基因序列比较所增强或取代。电子显微镜和分子测序都是既耗时又昂贵的方法，减慢了对新物种的描述。描述新藻类物种的耗时方法，藻类系统学家数量的减少，支持系统研究的资金的减少，以及生理学上未开发的地理区域协同作用，阻碍了获取藻类生物多样性的速度。
Algae are ubiquitous. They are the primary producers for all the oceans and seas, an area that covers 71% of the Earth's surface. Algae also occur in freshwater lakes, ponds and streams as well as on and in soil, rocks, ice, snow, plants and animals. In total, 40% of global photosynthesis is contributed by algae. The algae are tremendously diverse These are at least seven distinct phylogenetic lineages that arose independently during geological time and that evolved at different rates (based upon molecular clocks). Consequently, the algae in toto do not form a single, cohesive group, and they must be considered a polyphyletic assemblage. The red algal lineage has approximately 5000 recognized species (excluding nomenclatural synonyms. superfluous names, etc.) that are extant, and an estimated 500 to 15 000 new species remain to be described. The green algal lineage has approximately 16000 recognized extant species and up to 100 000 species that remain to be described. The chromophyte lineage has approximately 15 000 recognized extant species and from one to ten million species that remain to be described. The dinophycean lineage (primarily dinoflagellates) has approximately 3000 recognized, extant species and workers estimate that from 500 lo 8000 species remain to be described. The euglenophyte lineage has approximately 900 recognized extant species, and experts estimate that up to 1000 species remain to be described. The cryptophyte lineage is undergoing total revision and the numbers of species is very uncertain; perhaps 200 extant species are recognized and 1000 species remain to be described. The glaucophyte lineage has 13 recognized species, and perhaps several dozen species remain to be described. Since the 1960s, clonal culture followed by electron microscopic examination is often required before an alga can be identified or described as new. Recently, electron microscopy is being augmented by, or replaced by, gene sequence comparisons. Both electron microscopy and molecular sequencing are time consuming and expensive methods that slow the descriptions of new species. Time consuming methods for describing new algal species, a reduction in the number of algal systematists, a reduction in funds to support systematic research, and phycologically unexplored geographical areas act synergistically to hamper the rate of accessing algal biodiversity.