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Molecular Phylogeny and Cryptic Diversity of the Genus P hacus ( P hacaceae, E uglenophyceae) and the Descriptions of Seven New Species
Author(s) -
Kim Jong Im,
Shin Woongghi
Publication year - 2014
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/jpy.12227
Subject(s) - biology , sensu , phylogenetic tree , monophyly , genus , phylogenetics , botany , molecular phylogenetics , clade , chloroplast dna , zoology , evolutionary biology , gene , genetics
The photosynthetic euglenoid genus P hacus is commonly found in freshwater; it is characterized by a rigid to semi‐rigid cell, usually flat with numerous small discoid chloroplasts without pyrenoids. To understand the phylogenetic relationships among P hacus species, we used combined cytoplasmic SSU and LSU rDNA and plastid‐encoded SSU and LSU rDNA sequence data from 82 strains, including seven L epocinclis , three D iscoplastis , one E utreptia , and two E utreptiella strains, as well as morphological data. The combined molecular dataset was analyzed using B ayesian and maximum likelihood methods. The resulting tree revealed that the genus P hacus was not monophyletic and fully resolved the phylogenetic relationships among eight lineages that were congruent with unique morphological characters in each clade. Molecular phylogeny and detailed morphological data led to the descriptions of seven new species: P . brevisulca , P . claviformis , P . hordei‐formis , P . longisulca , P . minimus , P . paraorbicularis, and P . viridioryza . The new species were well supported as independent species and formed close relationships with small P hacus species and P . orbicularis in the tree. In addition, the new species had unique molecular signatures and showed high genetic diversity. Although the strains of P . orbicularis sensu Hübner were morphologically very similar, the phylogenetic analyses and genetic diversity suggested that P . orbicularis sensu H übner should be divided into two subclades.