한국 연안에 출현하는 저서 부착 와편모조류 5종에 대한 분자계통학적 위치와 형태 및 생리적 특성

Abstract

In study is to provide the understanding of phylogenetic positions on and the intra-specific variable morphological information and inform predictive occurrence based on effects of temperature, salinity and irradiance of five epiphytic dinoflagellates isolated from Korean coastal waters. We studied throughout 17 sampling sites on the eastern and southern coasts and Jeju Island of the Korea during April and August of 2013. Isolated cells were identified as Coolia monotis Meunier, Ostreopsis cf. ovata, Gambierdiscus cf. yasumotoi Holmes, Amphidinium operculatum Claparede et Lachmann, Amphidinium carterae Hulburt with light microscopy (LM) including epifluorescence microscopy, and scanning electron microscopy (SEM). The molecular phylogenetic analyses were performed for 19 strains of the four genera on the large subunit rDNA (LSU) region. Our data provide the detail description and distinct phylogenetic and biogeographic information about four genera isolated from Korean coasts compare with previously reported that. In the phylogenetic analyses showed that A. carterae is comprised of at least four distinct lineages separated by genetic distances. Korean four A. carterae strains made a genetically separated clade from the previously reported strains. And their cingulum position was different from the description of A. carterae Hulburt. Also A. operculatum was divided by two clades. Korean two strains isolated eastern sea were formed one clade, whereas another clade of strains has been isolated from New Zealand. The Korean O. cf. ovata strains formed a distinct clade with another strain (HE793379) also isolated from Korea certainly. The C. monotis species of one clade were isolated from Pacific areas where Korea (in this study) and New Zealand. And those of another clade were originated from Mediterranean areas. However, C. monotis strains have a small genetic distance with New Zealand strains. The Gambierdiscus strains isolated from Korea was morphologically different from G. yasumotoi Holmes 1998. in size of cells, dorsoventral ratio and shape of first apical plate. The phylogenetic tree of Gambierdiscus genera showed that Korean G. yasumotoi formed a distinct clade, separated from the other clades consisted of the other Gambierdiscus species, with G. yasumotoi and G. ruetzleri. However, LSU rDNA sequences of G. cf. yasumotoi were different from that of the G. yasumotoi (EF202967), 0.04 and G. ruetzleri (EU498084), 0.07. This study examined the effects of temperature (13.2-32.28℃), salinity (21.7-36.6) and irradiance (50-388 μmol photons m-2s-1) on growth of Gambierdiscus, Ostreopsis, Coolia, and Amphidinium. Depending on species, temperature maximum growth occurred varied between 20.0 and 35.1 ℃. The lower temperature limits for all species were 13.8-17.1℃. Salinities maximum growth occurred varied between 28.4 and 36.7, while the lowest salinities supporting growth ranged from <25 to 21.7 These data indicated that Gambierdiscus, Ostreopsis, Coolia species are more tolerant of lower salinities than is generally appreciated. Growth of all species began to decline markedly as salinities exceed 35.1-39.4. All five species were adapted to relatively low light conditions, exhibiting growth maxima at 60-100 μmol photons m-2s-1 and requiring only 20 μmol photons m-2s-1 to maintain growth. As a result, Gambierdiscus, Osteropsis have been known to live in tropic waters. We suppose that these were would inflow and settled into Korean waters.