Morphology and molecular characterization of Pseudo-nitzschia (Bacillariophyceae) from Malaysian Borneo, including the new species Pseudo-nitzschia circumpora sp. Nov

Hong-Chang, Lim and Chui-Pin , Leaw and Nyun-Pau Su, Suriyanti and Sing-Tung, Teng and Usup, Gires and Mohammad Noor, Normawaty and Lundholm, Nina and Kotaki, Yuichi and Po-Teen , Lim (2012) Morphology and molecular characterization of Pseudo-nitzschia (Bacillariophyceae) from Malaysian Borneo, including the new species Pseudo-nitzschia circumpora sp. Nov. Journal of Phycology, 48 (5). pp. 1232-1247. ISSN 1529-8817

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Abstract

Field sampling was undertaken to investigate the occurrence of Pseudo-nitzschia Peragallo species in eight locations along the coast of Malaysian Borneo. A total of 108 strains of Pseudo-nitzschia species were isolated, and their morphology examined with SEM and TEM. Additionally, molecular data from nuclearencoded partial LSU rDNA, and ITS regions, were characterized. A total of five species were confidently identified based on a combination of distinct morphological characteristics and supporting molecular evidence: P. brasiliana Lundholm, Hasle & Fryxell, P. cuspidata (Hasle) Hasle, P. dolorosa Lundholm & Moestrup, P. micropora Priisholm, Moestrup & Lundholm, and P. pungens (Grunow) Hasle var. pungens. However, one morphotype from Sarawak, while somewhat similar to P. caciantha, showed significant morphological distinction from this and any other of the currently described species. Most notably this morphotype possessed a characteristic pore arrangement in the poroids, with the fine pores in each perforation sector arranged in circles. Pairwise sequence comparison of the LSU rDNA between this unidentified morphotype and P. caciantha Lundholm, Moestrup & Hasle, revealed 2.7% genetic divergence. Phylogenetic analyses strongly supported the monophyly of the morphotype. Based upon these supporting data it is here described as a new species, Pseudo-nitzschia circumpora sp. nov. A key to the six species of Pseudo-nitzschia from Malaysian Borneo is presented. Molecular signatures for all species were established based on structural comparisons of ITS2 rRNA transcripts.

Item Type:	Article (Journal)
Additional Information:	6635/26256
Uncontrolled Keywords:	Malaysia;molecular signature;morphology;Pseudo-nitzschia circumpora;Pseudo-nitzschia
Subjects:	Q Science > Q Science (General)
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Science > Institute of Oceanography and Maritime Studies
Depositing User:	Dr Normawaty Mohammad Noor
Date Deposited:	01 Nov 2012 09:43
Last Modified:	06 Nov 2012 13:35
URI:	http://irep.iium.edu.my/id/eprint/26256

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