Morphological comparison and molecular marker screening of three Skeletonema species found in Changjiang(Yangtze)River Basin  

作　　者：Jingwen HU Yuxin YI Zhengxin YANG John Patrick KOCIOLEK Pan YU Quanxi WANG Qingmin YOU 

机构地区：[1]College of Life Sciences,Shanghai Normal University,Shanghai 200235,China [2]Museum of Natural History,University of Colorado,Boulder 80309,USA [3]College of Environmental and Geographical Sciences,Shanghai Normal University,Shanghai 200235,China

出　　处：《Journal of Oceanology and Limnology》2024年第3期923-942,共20页海洋湖沼学报（英文）

基　　金：Supported by the National Natural Science Foundation of China(No.32170205);the Natural Science Foundation of Shanghai(No.21ZR144730)。

摘　　要：In our recent investigations of diatom diversity,we studied three species,namely,Skeletonema costatum,Skeletonema subsalsum,and Skeletonema potamos.Although they have been found frequently in Changjiang(Yangtze)River Basin,their morphological and molecular identification is difficult in taxonomy.Therefore,to integrate morphological and molecular biological approaches,we compared systematically their morphological characters and performed phylogenetic analysis.Twelve strains of Skeletonema were collected and isolated from Shanghai and Jiangsu,China,and their morphological characteristics were examined by light microscopy(LM)and the scanning electron microscopy(SEM).Based on morphological comparison,we determined that S.potamos is easy to distinguish from the other two species.The heavily silicified areolae,undulated or cleft distal ends of terminal fultoportula processes(TFPPs),absence of basal pores of fultoportula processes(FPPs),the rootlike protrusions of FPPs,and no interlocking connection are the stable characteristics that can be used to identify S.potamos.However,there are only two features that can distinguish S.costatum from S.subsalsum,namely the location of terminal rimoportulae(TRPs)and the distal shape of TFPPs.In addition,we amplified and sequenced nine common genetic markers from the strains,from which 101 sequences were obtained,constructed phylogenetic trees based on the nine genes and evaluated that seven genes can be used to identify S.potamos,and revealed that S.subsalsum is the closest known relative of S.costatum,and only ATP synthetase beta-subunit gene(atp B)is able to distinguish them from each other,which strongly support that it is an effective molecular marker for Skeletonema.This work provided a theoretical basis for the taxonomic study of Skeletonema.

关 键 词：SKELETONEMA Changjiang River morphological change distinguishing morphological characteristics molecular marker 

分 类 号：Q944[生物学—植物学]