In this study, aquatic and aerial algae were collected in various environments in Hongcheon-river of Gangwan-do between December 2011 and June 2012, with the aim of adding newly described genera and species to the Korean flora. As a result, five genera and eight species were recorded for the first time in Korea. These newly recorded genera and species were
Today, the ecosystem of the earth is facing the problem of reducing species diversity due to various factors (Jaenike 2007, Butchart et al. 2010). Advanced countries have been conducting continual research on about species diversity in order collect useful genes and construct gene banks for various organisms (Na et al. 2012). The South Korean government, for example, has been studying unexplored species and attempting to secure living resources and native Korean specimens since 2006. Microalgae are a useful species due to their physiological characteristics, which make them a widely used tool for genomics and proteomics (Shay 1993, Minowa et al. 1995, Lee et al. 2010). However, studies on the environments that algae inhabit in Korea are less advanced than those in other countries. Furthermore, Korean native species have not been precisely collected, as investigations have lacked the professional manpower to perform sufficiently thorough work (Na et al. 2012). Also, few studies on microalgae have been conducted and are largely limited to species of industrial importance (Um and Kim 2009, Yoo et al. 2010, Lee et al. 2010). Studies on algae in Korea have focused especially on aquatic algae, while those on aerial algae in Korea are less advanced than in other countries (kaloud 2009, Khaybullina et al. 2010). In Hongcheon-river, specifically, research on algae diversity has only looked at the unrecorded order Chlorococcales (Shin et al. 2013). Thus, in this study, aquatic and aerial algae were collected in various environments within Hongcheon-river, with the aim of adding newly described genera and species to the known Korean flora.
Freshwater and aerial algae were sampled in Hongcheon-river at Gangwon-do, Korea, from December 2011 to June 2012 (Fig. 1 and Table 1). Freshwater algae samples were collected from planktonic, periphytic, or subaerial habitats by using a phytoplankton net and a soft brush. Aerial algae samples were collected from stones, soil, and mosses by using a soft brush and a spatula. Each sample was sealed and refrigerated in a light-tight container with sterilized distilled water and transferred to the laboratory (Crispim et al. 2004). Some of the samples were fixed and stored in 1％ formalin. Enriched cultures of aerial algae were made in Bold’s basal media (Stein 1973) and maintained in the algal culture collection of Kyonggi University (ACKU). The taxonomic classification system used was based on John et al. (2002, 2011) and Algaebase (Guiry and Guiry 2014), and taxa were identified based on the work of Prescott et al. (1972, 1977, 1981, 1982), Prescott (1973), Hirose et al. (1977), Komárek and Fott (1983), Chung (1993), and Wehr and Sheath (2003). The samples were examined at ×400–1,000 magnification under a light microscope (BX41; Olympus, Tokyo, Japan) equipped with Nomarski differential interference optics. Species were illustrated by using a drawing attachment together with light microscope photographs.
In this study, five genera were first recorded in Korea. In addition, eight species belonging to these five genera were added to the known Korean flora. The newly recorded genera for Korea are
Cells 14-20 μm wide, usually 2-3 times as long as the width. Cells filamentous, cylindrical, with both sides rounded, one end slightly narrowed. Cell wall is composed of several layers, with a parietal star-shaped chloroplast. Cell walls are generally thin, but old cell walls are sometimes thick. This species is abundantly distributed in freshwater (John et al. 2011). In this study, we expected this species to inhabit places with attached stone samples on the waterside and planktonic samples (Table 2). John et al. (2011) reported that
This genus was first named by Borzì (1883) and is newly recorded in Korea by this study. Genus
Cells irregular, spherical, cylindrical, 11-25 μm in diameter with irregularly branched cell. Last cell fragment is the smallest. Chloroplast parietal, with starch in the center of cells. Cell wall usually thick, lacking pyrenoid. In a study by John et al. (2011), this species was found in aquatic environments such as bogs and pools, as well as in aerial environment, including mosses and plants. In this study, we found this species in freshwater (Table 2).
This genus was named by Wille (1901) and is newly recorded in Korea by this study.
Cells irregular, spherical, cylindrical, 5-13 μm in diameter, with irregular branching. Last fragment cell is the smallest. Chloroplast parietal, with pyrenoid in the center of the cell. This species has been found on both artificial and natural matrices in water (John et al. 2011). In this study, we found this species on stones lying on the shore (Table 2).
Cells cylindrical, ellipsoidal or spherical, 3-9 μm long, 2-3 μm wide. Smaller than
Cells cylindrical with both sides rounded, 8-17 μm long, 3-5 μm wide. Cells solitary, with thin cell wall. Chloroplast parietal. The morphological characteristic of this species is that it has a starch envelope pyrenoid while other
This genus was named by Hibberd (1981) and is newly recorded in Korea by this study. This genus has morphological characteristics of a yellow-green chloroplast, a polyhedral pyrenoid and a red eyespot.
Cells usually solitary, spherical or ellipsoidal, 5-22 μm in diameter. Shape of cell changes from spherical to pyramidal over cell life cycle. Cell wall is thin. Chloroplast is parietal with green color, but old cells change from yellow-green to yellow color. The cells have a polyhedral pyrenoid and one red eyespot. Škaloud (2009) and Ettl and Gärtner (1995) reported this species to be aerial algae. In the current study, this species was sampled and isolated from humid substrate as moist soils.
This genus was named by Pascher (1939) and is newly recorded in Korea by this study. Genus
The cell is 7-22 μm long, 3-4 μm wide and usually exists in solitary; but occasionally, two cells are attached together. The cells are kidney-shaped, lunate, or cylindrical. The chloroplast is parietal, with 1-3 fragments, lacking a pyrenoid. John et al. (2002) reported that it is commonly found in acidic to weakly alkaline water, moorlands and bogs. However, we found it in the aerial environment, on mosses and rocks.
This genus was named by Silva (1979) and is newly recorded in Korea by this study. Genus
Cells are unbranched and filamentous, 6-15 μm long, 3-5 μm wide. Cells are cylindrical, and the cell-linked parts become narrow. Each cell has two chloroplasts, and those are parietal. This species is reported to be aerial algae (Guiry and Guiry 2014), and we also isolated this species in moist soil samples.
The morphological characteristics of the eight taxa identified in this study largely correspond to their reported characteristics. However, some differences from previous descriptions were found.