中国淡水胭脂藻属植物形态及分子系统发育分析  

MORPHOLOGY AND MOLECULAR PHYLOGENETIC ANALYSIS OF FRESHWATER HILDENBRANDIA IN CHINA

作　　者：南芳茹 李娟 刘旭东 冯佳[1] 刘琪[1] 吕俊平[1] 谢树莲[1] NAN Fang-Ru;LI Juan;LIU Xu-Dong;FENG Jia;LIU Qi;Lü Jun-Ping;XIE Shu-Lian(School of Life Science,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学生命科学学院,太原030006

出　　处：《水生生物学报》2021年第6期1341-1350,共10页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(31800172,31670208和41871037)资助。

摘　　要：以云南省玉溪市和河南省焦作市新采集的2株淡水胭脂藻标本为材料,对其进行形态特征观察和分子系统发育分析,联合我国已报道的其他胭脂藻序列信息,构建该属植物可靠的系统发育关系。根据其现代地理分布模式,对胭脂藻属进行了祖先地理起源重建。基于rbcL、psbA和UPA序列,利用贝叶斯法、最大似然法和邻接法构建的系统发育树高度一致,研究中的标本与鸡公山胭脂藻H.jigongshanensis聚合为一个独立分支,并得到了很高的支持率,根据分子生物学证据,将其鉴定为鸡公山胭脂藻。通过研究中所采集2株鸡公山胭脂藻的形态特征比较,发现传统的形态分类特征包括藻体高度和细胞直径,在不同的环境条件下是可变的,不适合作为胭脂藻属植物种类鉴定的依据。对于胭脂藻属这一形态结构较为简单的类群,必须借助分子生物学证据和系统发育分析手段对其进行种类鉴定和系统发育分析。分子系统发育分析结果表明,中国特有种鸡公山胭脂藻H.jigongshanensis形成单系类群,其与日本胭脂藻H.japananense亲缘关系较近,所有淡水胭脂藻种类形成一个独立的聚类群,与海洋种类遗传差异较大。祖先地理重建的分析结果表明,淡水胭脂藻的祖先起源地位于北美洲,然后逐渐向东加勒比海区域、拉丁美洲和欧亚大陆扩散,形成现代地理分布模式。胭脂藻属独特的种类地理分布特点,可能与其较为古老的起源时间和漫长的进化历史相关,同时淡水胭脂藻在北美洲区域起源时间较早,进化历史漫长,遗传多样性大,这与该地理区域分布的种类H.angolensis为多系类群是相一致的。This study explored morphological observation and molecular phylogenetic analysis of two freshwater Hildenbrandia specimens from Yuxi,Yunnan Province(encoded as YZYUNNAN)and Jiaozuo,Henan Province(encoded as YZHENAN)in China.Morphological observation and molecular phylogenetic analysis were conducted on these specimens.Phylogenetic relationship of genus Hildenbrandia was constructed based on the obtained gene sequence and related molecular data previously reported in China.Ancestral geographical origin of freshwater Hildenbrandia was inferred based on reliable phylogenetic relationship and modern distribution pattern of each sample.The results are consistent using Bayesian Inference,Maximum Likelihood and Neighbor-joining based on rbcL,psbA and UPA sequences.The genetic distances of three molecular sequences between specimens collected and H.jigongshanensis were smaller compared with another freshwater species.The uncorrected p-distances of rbcL sequences between specimens and H.jigongshanensis were within intraspecific divergence of freshwater Hildenbrandia species.Phyloge-netic trees showed that specimens YZYUNNAN and YZHENAN formed an independent branch with H.jigongshanen-sis,and obtained high supporting values.Specimens YZYUNNAN and YZHENAN shared close relationship with H.ji-gongshanensis based on molecular phylogeny.The morphological measurements of collected specimens were in con-sistent with another freshwater Hildenbrandia species H.rivularis.It has been acknowledged that the widely reported freshwater species H.angolensis and H.rivularis are distinguished by morphometric measurements,with H.angolen-sis characterized by smaller mean cell and filament dimensions(cells 4.0×4.4μm,filaments 46.5μm)and H.rivularis by larger parameters(cells 5.8×6.6μm,filaments 55.3μm).H.jigongshanensis is separated from other freshwater members by significantly larger cell dimensions(9.8-19.6)×(9.9-10.4)μm and filament height(364-409μm).The morphological measurements of H.japananense,the cell size(8.4×10.5μm)and f

关 键 词：淡水胭脂藻 形态特征 RBCL PSBA UPA 系统发育 祖先地理起源 

分 类 号：Q941[生物学—植物学]