한국산 청각 (녹조) 속의 분류

Abstract

Codium Stackhouse, which is a cosmopolitan green algal genus distributed worldwide, comprises of about 140 species. Thallus shows various forms. However, its structure is relatively simple, and is composed of coenocytic filaments which are surrounded by a cortex of utricles. Seventeen species of Codium are currently recorded in the marine algal flora of Korea. During the present study, 14 species were collected from the coasts of Korea, and taxonomic examinations were made based on morphological and molecular data. As a result, three major clades were recognized in phylogenetic tree based on rbcL sequences. Clade A involves 6 species including C. arabicum, and is supported strongly by crustose thallus. Clade B shares globose form, erect and cylindrical form, and erect and flattened form of thallus, involving 7 species together with C. minus. By contrast, C. fragile which shows erect and cylindrical form of thallus nests in Clade C. Of these three clades, Clade A which is referred to Sect. Adharentia forms strongly monophyletic group as a basal clade of the phylogenetic tree. Several aspects of the morphological features, such as thallus form, utricle, hair cell, and gametangium, found in Codium are discussed taxonomically in detail, and a key to the Korean species of Codium examined in the present study is provided.