New species of freshwater Ulva, Ulva limnetica (Ulvales, Ulvophyceae) from the Ryukyu Islands, Japan
New species of freshwater Ulva, Ulva limnetica (Ulvales, Ulvophyceae) from the Ryukyu Islands, Japan
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DOI：
10.1111/j.1440-1835.2009.00525.x
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发表时间：
2009-06-01
影响因子：
1.5
通讯作者：
Shimada, Satoshi
中科院分区：
文献类型：
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作者：
Ichihara, Kensuke;Arai, Shogo;Shimada, Satoshi
湖沼石莼（Ulva limnetica Ichihara et Shimada，sp. nov.）为石莼目石莼科石莼目（Ulvales，Ulvophyceae）的一个新种，分布于日本琉球群岛，其特征为叶状体为：（i）分枝、管状、易碎、具皱纹;（ii）高度可达80 cm，直径可达2 cm;（iii）颜色为淡至黄绿色;（iv）通过四鞭毛虫群体进行无性繁殖。在菌柄的细胞层的外侧有管状的延伸。湖沼石莼在叶绿体分布、分枝方式、细胞核数目和大体形态上与具有相似叶状体的种有所区别。它还通过核编码的18 S核糖体RNA基因、内部转录间隔区2区和质体编码的核酮糖-1，5-二磷酸羧化酶/加氧酶基因大亚基（rbcL）的序列来区分。湖沼石莼与其他石莼属内的早期分化谱系聚类。
Ulva limnetica Ichihara et Shimada, sp. nov. (Ulvales, Ulvophyceae) is described from the Ryukyu Islands, Japan, and is characterized by thalli that are: (i) branched, tubular, fragile and wrinkled; (ii) up to 80 cm in height and up to 2 cm in diameter; (iii) light to yellowish green in color; and (iv) having an asexual reproduction by means of quadriflagellate swarmers. Rhizoidal cells bear tubular extensions on the outside of the cell layer in the stipe. Ulva limnetica is distinguished from species with similar thalli by chloroplast disposition, branching pattern, number of pyrenoids per cell and gross morphology. It is also distinguished by sequences of the nuclear-encoded 18S ribosomal RNA gene, internal transcribed spacer 2 region and the plastid-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxgenase gene (rbcL). Ulva limnetica was clustered with other Ulva species in an early diverging lineage within the genus.