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Chlamydomonas neoplanoconvexa nom. nov. and its unique phylogenetic position within Volvocales (Chlorophyceae)
Author(s) -
Nakada Takashi,
Tomita Masaru
Publication year - 2011
Publication title -
phycological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.438
H-Index - 44
eISSN - 1440-1835
pISSN - 1322-0829
DOI - 10.1111/j.1440-1835.2011.00617.x
Subject(s) - pyrenoid , biology , chlamydomonas , clade , botany , phylogenetic tree , phylogenetics , chlorophyceae , evolutionary biology , chloroplast , gene , algae , genetics , chlorophyta , mutant
SUMMARY Chlamydomonas Ehrenb. is a unicellular volvocalean genus consisting of 400–600 species, most of which are known solely based on microscopy. In this study, a newly isolated strain of Chlamydomonas neoplanoconvexa (M. O. P. Iyengar) Nakada nom. nov. (≡ Chlamydomonas planoconvexa M. O. P. Iyengar non J. W. G. Lund) was examined using light microscopy and combined 18S r RNA, rbc L and psa B gene phylogeny. The C. neoplanoconvexa strain was quite similar to Chlamydomonas perpusilla (Korshikov) Gerloff in terms of its small fusiform vegetative cells (∼10 µm in length), parietal chloroplast containing a single pyrenoid, and nucleus posterior to the pyrenoid. However, C. neoplanoconvexa was distinguished from C. perpusilla based on the morphology of the papillae and pyrenoids. The two species belong to the clade Caudivolvoxa in the order Volvocales, but are distantly related to each other. Chlamydomonas perpusilla was shown to be sister to Chlorogonium Ehrenb. (clade Chlorogonia , within Caudivolvoxa ), while C. neoplanoconvexa represented a second basal lineage within Caudivolvoxa , next to the clade Characiosiphonia . Although the morphology of C. neoplanoconvexa was not particularly outstanding, its unique phylogenetic position will encourage further investigation of this species and its uncultivated relatives.