Taxonomy and phylogeny of the section Chaetoceros(Chaetocerotaceae,Bacillariophyta),with description of two new species  

作　　者：Xudan LU Mengyi ZHAI Nina LUNDHOLM Yang LI 

机构地区：[1]Guangdong Provincial Key Laboratory of Biotechnology for Plant Development,Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring,College of Life Science,South China Normal University,Guangzhou 510631,China [2]Natural History Museum of Denmark,University of Copenhagen,Copenhagen K 1353,Denmark

出　　处：《Journal of Oceanology and Limnology》2024年第4期1286-1311,共26页海洋湖沼学报（英文）

基　　金：Supported by the Joint Fund of National Natural Science Foundation of China and Chinese Shandong Province(No.U 2106205);the National Natural Science Foundation of China(No.32170206);the National Key Research and Development Program of China(No.2022YFC3105201)。

摘　　要：Chaetoceros Ehrenberg is one of the most diverse genera of planktonic diatoms.The species in section Chaetoceros are characterized by cells and setae having numerous chloroplasts and being widely distributed.However,the delimitations of some species are problematic because of limited morphological information in the classical descriptions.Monoclonal strains of the section Chaetoceros were established,morphological features were studied using light and electron microscopy,and the hypervariable D 1-D 3 region of the nuclear ribosomal large subunit gene was sequenced to address phylogenetic relationships.Fifteen species belonging to the section Chaetoceros were recorded,including two new species,C.hainanensis sp.nov.and C.tridiscus sp.nov.Chaetoceros hainanensis was characterized by straight chains,narrowly lanceolate to hexagonal apertures,sibling setae diverging in nearly right angles,stipule-shaped spines on terminal setae and arrowhead-shaped spines on intercalary setae.C.tridiscus had short straight chains,narrowly lanceolate apertures,arrowhead-shaped spines and circular poroids arranged in a grid pattern on terminal and intercalary setae.The phylogenetic analyses revealed six groups formed by 19 species within the section Chaetoceros,which was found to be monophyletic.The subdivision of the section is still not well understood.The morphological characters within each group varied considerably and molecular information on more species are needed to enrich the phylogenetic profiling.

关 键 词：morphology large subunit ribosomal RNA encoding gene(LSU) section Chaetoceros Chaetoceros hainanensis Chaetoceros tridiscus 

分 类 号：Q949.2[生物学—植物学]