文报道了采自广西防城港和广东湛江的中国石莼属海藻一新记录种——大野石莼 Ulva ohnoi Hiraoka & S.Shimada 2004, 详细描述了其形态特征并进行了多基因标记分析。结果表明, 大野石莼具附着个体和漂浮个体, 藻体呈浅绿色, 长 15-60cm, 单生或丛生, 质脆, 易撕裂, 外观呈圆形、长卵形或不规则形; 藻体细胞表面观呈方 形或多边形, 不规则排列, 边缘具齿状凸起; 藻体上部和中部相似, 细胞尺寸为 10-20×5-15µm, 厚度为 20-45µm; 藻体基部细胞近圆形, 尺寸为10-30×10-22µm, 基部厚度为 70-90µm。rbcL 和 tufA 基因序列分析结果显示, 本研 究采集的样本均与 GenBank 中的大野石莼序列聚在一支, 有高 Bootstrap 值与后验概率支持, 彼此间遗传距离为 0-0.1%。本研究丰富了我国石莼属的物种多样性, 强调了分子生物学技术在绿藻物种鉴定中的重要性, 为我国海 藻资源保护及利用提供了基础分类学资料。

This study reports a new record species of Ulva algae from China, Ulva ohnoi Hiraoka & S. Shimada 2004, collected from Fangchenggang, Guangxi and Zhanjiang, Guangdong. The morphological characteristics are described in detail, and multi-gene marker analysis was performed. The results show that Ulva ohnoi has both attached and floating individuals. The thallus is light green, ranging from 15 to 60 cm in length, and can be solitary or tufted. The tissue is brittle and easily torn, with a shape that is round, ovate, or irregular. The surface cells of the thallus are square or polygonal, arranged irregularly, with jagged protrusions along the edges. The upper and middle parts of the thallus are similar, with cell dimensions of 10-20 × 5-15 µm, and thickness of 20-45 µm. The basal cells are nearly round, measuring 10-30 × 10 22 µm, with a thickness of 70-90 µm. Analysis of rbcL and tufA gene sequences revealed that the samples collected in this study clustered with the type specimens of Ulva ohnoi, supported by high bootstrap values and posterior probabilities, with a genetic distance of 0 between them. This study enriches the species diversity of the Ulva genus in China, emphasizes the importance of molecular biology techniques in the identification of green algae species, and provides fundamental taxonomic data for the protection and utilization of marine algae resources in China.