Morphology,molecular phylogeny and biogeography revealed two new Pseudo-nitzschia(Bacillariophyceae)species in Chinese waters  

作　　者：Biao-Biao Niu Qi-Xiang Zheng Yang Liu Nina Lundholm Sing Tung Teng Xu-Dan Lu Rui-Wei Ran Li Zhang Yang Li 

机构地区：[1]Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring,Guangdong Provincial Key Laboratory of Biotechnology for Plant Development,College of Life Science,South China Normal University,Guangzhou,510631 China [2]Key Laboratory of Tropical Marine Bio-Resources and Ecology,Guangdong Provincial Key Laboratory of Applied Marine Biology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou,510301 China [3]Natural History Museum of Denmark,University of Copenhagen,Copenhagen K,1353 Denmark [4]Faculty of Resource Science and Technology,Universiti Malaysia Sarawak,Kota Samarahan,94300 Malaysia

出　　处：《Journal of Systematics and Evolution》2024年第4期621-636,共16页植物分类学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(32170206);National Key Research and Development Program of China(2022YFC3105201);Joint Fund of National Science Foundation of China and Chinese Shandong Province(U2106205);Guangzhou Basic and Applied Basic Research Foundation(2021A1515010786).

摘　　要：Pseudo-nitzschia is a group of widely distributed planktonic diatoms.Some species produce the neurotoxin domoic acid.Herein,two new Pseudo-nitzschia species were described from Chinese coastal waters and the South China Sea after combining morphological and molecular data,together with biogeographical traits.Pseudo-nitzschia punctionis sp.nov.was similar to Pseudo-nitzschia bipertita morphologically,but differed in poroid structure,which was undivided in P.punctionis but divided in two sectors in P.bipertita.This difference corresponded to the presence of two hemicompensatory base changes(HCBCs)in the secondary structure of internal transcribed spacer 2.Pseudo-nitzschia polymorpha sp.nov.was sister to Pseudo-nitzschia limii phylogenetically,but distinct by the various shapes of perforations on the valve and copula,which was supported by four HCBCs.In a metabarcoding analysis,multiple new ribotypes were identified within the two new species,and intraspecific genetic divergences were analyzed.Metabarcoding data revealed that P.punctionis had a broader temperature range(12.9–30.5℃)than P.polymorpha(22.3–30.5°C).Within the two new species,different traits were found among the amplicon sequence variants regarding temperature and biogeography,representing different microevolutionary directions under environmental selection.The two new species had different biogeographical traits when compared to their closely related species.Domoic acid was detected in strains of P.punctionis at a concentration of 13.5–17.7 fg/cell,but the toxin was not found in strains of P.polymorpha.A combination of characters based on laboratory strains and field metabarcoding data provided more data for delimiting Pseudo-nitzschia species and gave new insights into their diversity and biogeography.

关 键 词：China domoic acid metabarcoding MORPHOLOGY PHYLOGENY PSEUDO-NITZSCHIA 

分 类 号：Q95[生物学—动物学]