The genus Desmodesmus (Chodat) S.S. An, T. Friedl & E. Hegewald is ubiquitous in freshwater ecosystems, such as rivers, ponds, and wetlands. The actual species diversity and distribution of the genus is unknown because of morphological plasticity affected by habitats. Currently, 38 Desmodesmus species have been reported in Korea most of which transferred from the genus Scenedesmus recently, however, no phylogenetic relationships have been studied yet. Despite the challenges in analyzing relationships among Desmodesmus species through the morphology, ecology, and original description, this study focused on examining species-level relationships using the FBCC culture strains isolated from Korea. A total of 299 sequences (66 of 18S rRNA, 47 of atpB, 67 of petA, 52 of rbcL, and 67 of tufA) were newly determined and used for phylogenetic analysis. Four plastid genes tend to have higher variation than 18S rRNA in the variable sites and P-distance. From the combined phylogeny, the Desmodesmus included six clades such as Clade-1: D. pseudoserratus and D. serratus, Clade-2: D. communis, D. dispar, D. maximus, D. pannonicus, unidentified Desmodesmus sp., Clade-3: D. bicaudatus and D. intermedius, Clade-4: D. microspina, D. multivariablis, D. pleiomorphus, D. subspicatus, Clade-5: D. abundans, D. kissii, and D. spinosus, and Clade-6: D. armatus, D. armatus var. longispina, D. opoliensis, unidentified Desmodesmus spp. The new sequence data from FBCC strains will be used to identify species and study the molecular ecology of scenedesmacean green algae in freshwater ecosystems. The phylogenetic information from this study will expand our understanding of Desmodesmus species diversity in Korea.

국내 금강수계의 하구역에 위치한 하제항 암벽으로부터 기중성 남세균이 채집되어, 단조류 배양되었다. 2개의 남세균 배양주로부터 형태적 형질과 TEM에 의한 세포 미세구조 특징을 관찰하였다. 또한 16S rDNA 염기서열을 규명하여 BLAST 검색, 염기서열 유사도, 유전거리 및 계통 분석을 실시하였다. 국내 배양주는 Wilmottia murrayi와 계통학적으로 동일한 clade를 형성하였고, 99% 이상의 유사도를 나타냈다. TEM을 통한 세포 미세구조는 틸라코이드가 여러겹으로 세포막 주변에 분포하는 특징을 나타냄으로써 Coleofasciculaceae과의 특징과 일치하였다. 이상의 결과를 통해 W. murrayi를 국내 미기록속 및 미기록종으로 보고하였다.

This study was to investigate the difference of muscle activities in trunk, upper arm, and shoulder during push-up exercise based on 3 types of different arm position(posterior position, PP; normal position, NP; and anterior position, AP) and to provide effective push-up arm position for each muscle development. Fifteen healthy males(age, 21.5±0.5 years; height, 172.7±1.0 cm; body mass, 70.5±1.3 kg; shoulder width, 42.3±0.6 cm; and BMI, 23.6±0.5 kg/m2) participated in this study. PP, NP, and AP of the arm were used to conduct push-up exercise and 8 muscles(deltoideus p. acromialis: DA; pectoralis minor: PMI; pectoralis major: PMA; serratus anterior: SA; biceps brachii: BB; triceps brachii: TB; latissimus dorsi: LD; and infraspinatus: IS) of right side were selected to measure muscle activities. Total 9 counts of push-up exercise were conducted and EMG data signals of 5-time(from 3th to 7th) push-up movement were used for measuring muscle activities. PP push-up exercise showed that there was a significantly higher muscle activity of DA, PMI, PMA, SA, BB, LD, and IS(p<.05) and AP push-up exercise showed a significantly higher TB activity(p<.05). It would be suggested that different arm position evokes various muscle activities when conducting push-up exercise. PP would be the best push-up arm position for inducing various trunk, upper arm, and shoulder muscle activities compared to NP and AP.

The freshwater algae were collected at reservoirs and small ponds in Gyeonggi-do and Jeju-do on June 2016. Four species of Korean previously unrecorded algae were collected in domestic fresh waters: Coelastrum rugosum, Cosmarium baccatum, Cosmarium norimbergense and Staurastrum connatum var. pseudoamericanum. The morphological characteristics of the four taxa identified in this study were showed mostly similar to the characteristics of the previously reported characteristics. However, Cosmarium baccatum was larger than the previously recorded species and Staurastrum connatum var. pseudoamericanum was wider than the previously recorded species.