Pheopolykrikos hartmannii(W. Zimmermann) Matsuoka & Fukuyo 휴면포자와 유영세포: 형태적 특징 및 계통 분류, 발아에 미치는 온도 영향

Abstract

한국 남해역의 퇴적물에서 분리한 Pheopolykrikos hartmannii 휴면포자는 구형으로 밝은 갈색을 띠고 있으며, 표 면에는 길고 날카로운 돌기물이 관찰되고 내부에는 원형 질과 함께 한개의 붉은색 색소체(red accumulation)가 있다. 이 휴면포자는 5°C를 제외하고, 10°C에서 30°C 사이의 온도에서 발아하였고, 15°C와 20°C에서 높은 발아율(>90%)을 보였다. 휴면포자로부터 발아한 유영세포는 2개의 세포로 된 콜로니(two-celled colony) 형태로 관찰되었고, 전방세포의 상추구에서 고리 모양의 apical groove가 관찰되었다. 그리고 분자계통 분석 결과, Pheopolykrikos hartmannii는 Polykrikos종과 근연 관계로 확인되었다.

The germination characteristics of the resting cysts of Pheopolykrikos hartmannii collected from the southern coastal sediments of Korea were studied at different temperature conditions, and the morphology and phylogeny of the germlings were examined. The resting cysts of Ph. hartmannii were round and characterized by a red accumulation body and many arrow-like spines and could germinate at temperature of 10 to 30°C. High germination rates (>90%) were observed at 15 and 20°C, indicating that the resting cysts could act as seed populations for the bloom initiation of Ph. hartmannii in Korean coastal waters in early summer or early fall. The morphology of the germlings was generally consistent with the previous description, and an apical groove characterized by a fully enclosed loop was observed. Phylogenetic analysis based on large SubUnit (LSU) rRNA gene sequences revealed that the germlings shared an identical sequence with the Korean and American isolates of Ph. hartmannii and was a sister clade of Polykrikos species.