Morphology and molecular characterization of Pseudo-nitzschia (Bacillariophyceae) from Malaysian Borneo, including the new species Pseudo-nitzschia circumpora sp. Nov
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 dat...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Phycological Society of America
2012
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/26256/ http://irep.iium.edu.my/26256/ http://irep.iium.edu.my/26256/ http://irep.iium.edu.my/26256/1/Pseudo-nitzchia_circumpora.pdf |
| Summary: | 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. |
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