Hyunchur Shin

Taxonomy and distribution of Zostera (Zosteraceae) in eastern Asia, with special reference to Korea

Abstract The genus Zostera is a marine angiosperm in the family Zosteraceae, and five species have been reported in Korea. However, their morphological characteristics and distribution remain unclear. This study is intended to clarify the taxonomic characteristics and distribution of Zostera species in Korea. The results confirm that four species, Zostera japonica , Zostera marina , Zostera asiatica , and Zostera caulescens are distributed along the seacoast of South Korea, and these species are distinguished by the shape of leaf apex, number of leaf vein, number of fibrous strands between the midvein and its first side vein. Populations of Zostera caespitosa , which had previously reported from Korea, were not found. However, this species is easily distinguished from other Korean Zostera species by having an obcordate apex of leaf and rhizomes with extremely shortened internodes.

Speciation pathway of Isoetes (Isoetaceae) in East Asia inferred from molecular phylogenetic relationships.

Polyploidy plays an important role in the speciation of Isoëtes. Increasing our knowledge about the specific origin of each polyploid or phylogenetic relationship among species has been hampered because of conserved morphological variation and scarce habitats. We present several hypotheses concerning the speciation pathways of Isoëtes species distributed in East Asia. Our hypotheses are inferred from phylogenetic relationships that were elucidated using sequences of the internal transcribed spacer regions of nuclear ribosomal DNA, a second intron of LEAFY, and chloroplast DNA trnS-psbC spacer regions. These inferred phylogenetic relationships indicated that (1) the Chinese tetraploid, I. sinensis, is closely related to I. yunguiensis; (2) the Korean endemic species, I. hallasanensis, is an autotetraploid derived from I. taiwanensis or closely related taxa; (3) the hexaploid I. coreana forms a clade and has its closest evolutionary relationships with I. taiwanensis or I. hallasanensis; and (4) the Japanese hexaploid I. japonica is closely related to I. taiwanensis-I. coreana and I. sinensis-I. yunguiensis. These results suggest that interspecific hybridization and polyploidization have played central roles in speciation of East Asian Isoëtes. Furthermore, I. taiwanensis, an endemic species in Taiwan, has been involved in at least three cases of autopolyploid or allopolyploid speciation in East Asia.

Phylogenetic Relationship of Physocarpus insularis (Rosaceae) Endemic on Ulleung Island: Implications for Conservation Biology

Ulleung Island is a biodiversity hot spot harboring approximately 700 species of vascular plants with high number of endemic taxa. Physocarpus insularis, one of the 41 endemic species, has an extremely restricted distribution range on the very small, geologically young oceanic island. Phylogenetic relationship of P. insularis, however, remained highly controversial whether it is conspecific with Spiraea chamaedryfolia or a distinct species in Physocarpus, making it difficult to establish necessary conservation programs. We examined comparative morphology of Physocarpus and Spiraea and reconstructed the phylogeny of the rbcL, matK, ndhF, and trnL-trnF regions from the exemplars of Rosaceae. The results strongly supported the placement of P. insularis within Spiraea. Further phylogenetic analyses of tribe Spiraeeae based on the trnL-trnF and internal transcribed spacer data showed that P. insularis is closely related to S. chamaedryfolia. Morphological analysis revealed that P. insularis differs from S. chamaedryfolia by having larger leaf blades that are subcordate or truncate at base. Results of this study suggest that P. insularis should be recognized as a distinct taxon in Spiraea and that conservation efforts on Ulleung Island should focus on protecting its natural environment to conserve evolutionary patterns and processes in addition to specific conservation programs for species in peril.

Genetic diversity and its implications in the conservation of endangeredZostera japonica in Korea

As part of the on-going effort to conserve endangeredZostera japonica Ascher. & Graebn. in Korea, we have used RAPD band patterns to analyze its genetic structure and diversity. Out of 50 primers tested, 45 formed amplified bands with its genome, including 814 polymorphic and 28 monomorphic bands. The highest number (120) was found in the population of Geoje-do; the smallest (58), in Anmyeon-do. An examination of its genetic structure with AMOVA revealed that about 50% of all variations could equally be assigned to within and between populations. The statistical value Gst (index of genetic differences) was 0.49, and the average number of individuals exchanged between populations per generation (Nem) was calculated as 0.26. Although the habitats ofZ. japonica in Korea are disappearing at an alarming rate, significant levels of genetic variation still exist, especially in the Geoje-do population. Therefore, any recovery strategy for this endangered species should be planned on the basis of this genetic diversity among populations.

A phenetic analysis of Typha in Korea and far east Russia.

We used principal components analysis (PCA) and UPGMA cluster analysis to determine taxonomically definable limits and to estimate the phenetic relationships among four Typhaspecies from Korea and far east Russia using 25 quantitative characters. A scatter plot of the first two principal components resolved four clusters among the 77 specimens of Typha examined from Korea and far east Russia. The clusters corresponded to the four currently recognized species. Typha latifolia was readily distinguished from other species by having wide leaves and female inflorescences. Typha angustifolia was distinguished from T. orientalis and T. laxmanni by the long male inflorescences and large gap between male and female inflorescences. Typha laxmanniwas distinguished from T. orientalis by a higher ratio of male and female inflorescence lengths than others. UPGMA analysis also showed that individuals of Typha species from Korea and far east Russia form discrete clusters corresponding to four species.

Genetic diversity and population structure of diploid and polyploid species of Isoëtes in East Asia based on amplified fragment length polymorphism markers.

Isoëtes L. is critically endangered in areas of East Asia, including Taiwan, Japan, and South Korea. The genetic diversity and the population structure of six Isoëtes species from East Asia were evaluated by using amplified fragment length polymorphism (AFLP). Three AFLP‐selective primer combinations generated a total 923 amplification products, of which 919 (99.6%) were polymorphic. The levels of genetic diversity of two diploid species (I. taiwanensis [percentage of polymorphic loci \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Molecular evidence for hybrid origin of Aster chusanensis, an endemic species of Ulleungdo, Korea

( \mathrm{PPL}\,) =33.1\% {\mbox{--}} 38.3\%

Aster chusanensis (Asteraceae), a New Species from Korea

\end{document} ] and I. asiatica [ \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape