Actual distribution and present status of a threatened aquatic plant, Sagittaria aginashi (Alismataceae), in Korea

Takashi shiga,Kazumasa Tsubota,최혁재 한국식물분류학회 2017 식물 분류학회지 Vol.47 No.3

We evaluated the actual distribution, present status, and number of remnant individuals of Korean Sagittaria aginashi (Alismataceae) based on herbarium specimens and field surveys. We also reidentified Korean S. aginashi by analyzing sequences of the internal transcribed spacer (ITS) region. We found nine specimens of S. aginashi in herbaria from four localities housed at the Osaka Museum of Natural History (OSA) and at the Korea National Herbarium (KH). During our field research, we could not confirm the current statuses of two collection localities (Taereung and Ansan-si), though this was not the case for Ulsan-si. In addition, we found two new localities in Ulsan-si and Yangsan-si. These three remnant populations are distributed in wetlands in mountainous areas (elev. 480–740 m). With regard to the number of flowering and immature individuals in the three localities, there were <50 and <2,000, respectively, in total. ITS sequences demonstrated that the sequences of Korean and Japanese S. aginashi are uniform and distinct from other Sagittaria species. These results indicate that S. aginashi is a rare and threatened species in Korea. It should be listed as an endangered species on the Korean Red List and requires urgent protection by conservation programs, including the extensive surveys of other possible natural habitats.

New Mongolian records of two genera, seven species, and two hybrid nothospecies from Khar-Us Lake and its associated wetlands

Takashi shiga,Khurelbaatar Khaliunaa,Shukherdorj Baasanmunkh,Batlai Oyuntsetseg,Shotaro Midorikawa,Hyeok Jae Choi 국립중앙과학관 2020 Journal of Asia-Pacific Biodiversity Vol.13 No.3

During a floristic survey of Khar-Us Lake and its associated wetlands in Khovd Province, we found sevenspecies and two hybrid nothospecies that have not previously been recorded in Mongolia. These taxawere found in seven localities and included Hydrilla verticillata (L.f.) Royle, Najas flexilis (Willd.) Rostk. &W.L.E. Schmidt, N. minor All., and N. tenuissima (A.Braun ex Magnus) Magnus (Hydrocaritaceae);Potamogeton angustifolius J. Presl (Potamogetonaceae); Ceratophyllum platyacanthum Cham. subsp. oryzetorum (Kom.) Les (Ceratophyllaceae); Aldrovanda vesiculosa L. (Droseraceae); Veronica anagalloidesGuss. (Plantaginaceae); and Utricularia japonica Makino (Lentibulariaceae). Two of these genera,Hydrilla Rich. and Aldrovanda L., were also newly recorded from Mongolia. The addition of these taxa tothe present Mongolian flora list brings the numbers of registered taxa and genera to 3,200 and 686,respectively. The morphological characteristics, diagnostic features, and distribution of these taxa inMongolia are described in this report.

Obtaining new records of critically endangered Potamogeton praelongus (Potamogetonaceae) depending on groundwater springs in northern coastal areas of Hokkaido, Japan

Kohtaroh Shutoh,Tomoki Hirose,Takashi Shibahara,Takashi Shibahara,Mami Yamazaki,Takashi shiga 국립중앙과학관 2022 Journal of Asia-Pacific Biodiversity Vol.15 No.4

Potamogeton praelongus Wulfen is an aquatic macrophyte that is critically endangered in Japan. Althoughit is widely distributed throughout the boreal climatic zone, several European countries also recognize itas an endangered species. In Japan, it was once widely distributed throughout Hokkaido but has dis appeared or reduced in abundance at its known locations. During 2020e2021, we discovered five newlocations of this species in Wakkanai-shi and Sarufutsu-mura, Northern Hokkaido. Growing conditionsmust be suitable for this species in three of the five locations as it is present with several reproductiveshoots or is widely distributed in source pond or lake. However, conditions were poor in the other twolocations because few shoots were found or plants were observed only in 2020. Environmental condi tions in the new locations were similar to those reported in Europe and North America. In three of thefour locations at Wakkanai-shi, P. praelongus was distributed mainly along the eastern shore facing sanddunes or hills, suggesting that the distribution of this species depends on groundwater springs flowingfrom sand dunes or hills. Further populations may be discovered in the future by intensively surveyingareas near springs since many sand dune lakes and similar environments are present in Hokkaido.

The aquatic macrophyte flora of a small pond revealing high species richness in the Aomori Prefecture, Japan

Kohtaroh Shutoh,Takashi Yamanouchi,Syou Kato,Hiroki Yamagishi,Yusuke Ueno,Shiori Hiramatsu,Jun Nishihiro,Takashi shiga 국립중앙과학관 2019 Journal of Asia-Pacific Biodiversity Vol.12 No.3

A small semiartificial pond, revealing high species richness with respect to the aquatic macrophytes, was studied in the Aomori Prefecture, Japan. The pond had been completely formed ca. 10 years previously after excavation into a wet bog. To identify and evaluate its aquatic macrophyte flora during 2017–2018, we listed the species of aquatic vascular plants and charophytes in the pond and compared this list with those from the natural Japanese lakes using a database of aquatic flora in Japan. Two species were identified by molecular analyses because they lacked any reproductive organs, which were necessary for identifying the species level. We found a total of 57 taxa of aquatic macrophytes including 15 Red List species in Japan or Aomori Prefecture. Comparing the flora list with those from the 66 natural Japanese lakes surveyed since 2001, the pond was ranked fourth in the order of diversity (based on species richness) and rarity (based on numbers of Red List species). Therefore, the pond is an important aquatic environment in terms of aquatic macrophyte conservation in Japan. Interestingly, for a pond with such high species diversity, it is relatively small (0.14 km2), semiartificial, and relatively recently formed.

Contribution to the knowledge on the flora of Numrug Strictly Protected Area and some parts of East Mongolia

Baasanmunkh SHUKHERDORJ,Takashi shiga,Oyuntsetseg Batlai,Karsten Wesche,Christiane M. Ritz,Khaliunaa Khurelbaatar,김재영,Hyeong Jun Jo,바투후,정규영,최혁재 국립중앙과학관 2019 Journal of Asia-Pacific Biodiversity Vol.12 No.2

A floristic study of Eastern Mongolian Steppes has been conducted during the growing season of 2014 and continued in 2017, when we focused more on the Numrug Strictly Protected Area. Major objectives of this study were to assess floristic diversity of Eastern Mongolian Steppes and to review the conservation status of some endangered, rare, and very rare species. A total of 488 taxa of vascular plants, which belong to 254 genera of 75 families, including three endemic and 16 subendemic species were sampled. Among these were three endangered, three vulnerable, five near threatened, 16 very rare, and 39 rare species. Remarkably, Myriophyllum sibiricum and Typha latifolia are newly recorded for the flora of Mongolia. Moreover, new distribution records of some species were noted in four phytogeographical regions of Eastern Mongolia, such as Foothills of Great Khingan (30), East Mongolia (12), Mongolian Dauria (11), and Middle Khalkha (3). Finally, we assessed regional conservation status of the five species (two endangered and three vulnerable) from the East Mongolia using the International Union for Conservation of Nature Red List criteria and categories.

Invited Lectures : Particle Size Measurements in Sub-Micron Region Using Multi-Wavelength Linearly Polarized Lights

( Mikiya Araki ),( Kotaro Oki ),( Takashi Onishi ),( Seiichi Shiga ) 한국액체미립화학회 2013 한국액체미립화학회 학술강연회 논문집 Vol.2013 No.-

Feasibility of a newly developed non-intrusive particle size measurement method in sub-micron region using multi-wavelength polarized lights is investigated, experimentally. Figure 1 shows the optical setup. Polystyrene particles are used as the test particles, which are suspended in purified water. The arithmetic mean diameters of them are varied from 0.356 to 3.00 μm, which are previously measured with a conventional method (centrifugal sedimentation method). The laser beam passes through the test particles, and the scattered lights are acquired with a digital CCD camera set in parallel and perpendicular directions to the polarization plane of the incident light. Based on the Mie`s scattering theory, the ratio of scattered lights for these two components is given as a function of the particle diameter, the refractive index, and the wavelength of the incident light. By comparing the polarization ratio calculated analytically with those obtained experimentally, the particle size can be determined, which is called polarization ratio method. The major drawback of this method is the narrow measurement range, typically up to the order of 0.1 μm, which is attributed to the complicated behavior of the polarization ratio in the Mie scattering region. In order to extend the measurement range of conventional polarization ratio methods, three kinds of He-Ne lasers, whose wavelengths are 543.5, 594.1, and 632.8 nm, are used. The polarization ratios of the scattered lights are obtained from these scattered light images, and the acquired data are compared with the analytical values. Figure 2 shows the data comparison with a conventional method. It is shown that, by use of the multiwavelength polarization ratio method, the measurement range of the particle size can be extended up to the order of 3 μm, and that the accuracy of the results lies from 0.1 % to 7.6 %, when compared with the results of a centrifugal sedimentation method.

First record of Myriophyllum oguraense Miki (Haloragaceae) in Korea

최혁재,장주은,정선우,Takashi shiga 한국식물분류학회 2014 식물 분류학회지 Vol.44 No.2

Here we report a previously unrecorded species of Korean Myriophyllum L. (Haloragaceae). This taxon, M. oguraense Miki has been regarded as a Japanese endemic for some 60 years. Myriophyllum oguraense and its closely related M. verticillatum L. share the characteristic of having pectinate emergent leaves that are similar in shape to, but much smaller than, the submerged leaves. However, the primary characteristic that differentiates these taxa is the turion shape (club shaped in M. verticillatum and linear in M. oguraense). The common name, ‘Gin-dong-a-mul-su-sae-mi’ was also newly given considering its characteristic turion shape. Photographs and a key to Korean Myriophyllum species are provided in addition to complete descriptions including information on nomenclatural types, distributions and specimens examined.

Taxonomic identity of Landoltia punctata (Araceae, Lemnoideae) in Korea

이유리,Hyeok Jae Choi,Takashi shiga 국립중앙과학관 2020 Journal of Asia-Pacific Biodiversity Vol.13 No.3

The duckweed species, Landoltia punctata (G. Meyer) D. H. Les & D. J. Crawford (family, Araceae; subfamily,Lemnoideae; common name, dotted duckmeat) was found in artificial wetlands in Jeju SpecialSelf-Governing Province, Republic of Korea; however, it has no formal record in Korea. We identified thisspecies based on morphological characteristics and DNA sequences. We also checked Lemnoideaespecimens in the Korean and Japanese herbaria but found no specimens of La. punctata collected in Koreapreviously. The chloroplast DNA sequence (atpF-atpH) of the species collected from Jejudo was identicalto the other La. punctata sequences in the DNA Data Bank of Japan (DDBJ)/The European MolecularBiology Laboratory (EMBL)/GenBank. Their habitat environments and our herbarium research suggestthat this species has recently become distributed in Korea. This study also provides a key to closelyrelated taxa in the subfamily Lemnoideae, with descriptions of these species.

Molecular phylogenetic relationships among populations of Sagittaria aginashi Makino (Alismataceae) and endemic Chinese species

Kazumasa Tsubota,Kohtaroh Shutoh,Syou Kato,최혁재,Takashi shiga 국립중앙과학관 2019 Journal of Asia-Pacific Biodiversity Vol.12 No.1

The aquatic plant Sagittaria aginashi, which is an endangered emergent species distributed in SouthKorea, Japan, and the Russian Far East, has an unclear phylogeny and genetic structure. Phylogenetic treesof Sagittaria were constructed based on one nuclear ribosomal DNA (nrDNA) region and on threechloroplast DNA (cpDNA) regions. S. aginashi was included in a clade comprising three endemic ChineseSagitarria species characterized by the presence of small tubercles at the base of the axils. Furthermore,phylogenetic trees based on cpDNA sequences indicated that S. aginashi was more closely related toS. tengtsungensis than to two other species. S. aginashi exhibited little genetic variation, suggesting thatthis species had rapidly spread in these areas. With regard to factors associated with the rapid spread, weconsidered that multiple dispersal methods were involved, namely hydrochory via tubercles, endozoochorous long-distance dispersal, and anthropogenic impacts of rice farming on S. aginashi dispersal.

Usefulness of Simultaneous Magnetic Resonance Neurography and Apparent T2 Mapping for the Diagnosis of Cervical Radiculopathy

Enomoto Keigo,Eguchi Yawara,Sato Takashi,Norimoto Masaki,Inoue Masahiro,Watanabe Atsuya,Sakai Takayuki,Yoneyama Masami,Aoki Yasuchika,Orita Sumihisa,Narita Miyako,Inage Kazuhide,Shiga Yasuhiro,Umimura 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.1

Study Design: Retrospective observational study.Purpose: We investigated the correlation between T2 relaxation times and clinical symptoms in patients with cervical radiculopathy caused by cervical disk herniation.Overview of Literature: There are currently no imaging modalities that can assess the affected cervical nerve roots quantitatively.Methods: A total of 14 patients with unilateral radicular symptoms and five healthy subjects were subjected to simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement signaling (SHINKEI-Quant) using a 3-Tesla magnetic resonance imaging. The Visual Analog Scale (VAS) score for neck pain and upper arm pain was used to evaluate clinical symptoms. T2 relaxation times of the cervical dorsal root ganglia of the brachial plexus were measured bilaterally from C4 to C8 in patients with radicular symptoms and from C5 to C8 in healthy controls. The T2 ratio was calculated as the affected side to unaffected side.Results: When comparing nerve roots bilaterally at each spinal level, no significant differences in T2 relaxation times were found between patients and healthy subjects. However, T2 relaxation times of nerve roots in the patients with unilateral radicular symptoms were significantly prolonged on the involved side compared with the uninvolved side (p<0.05). The VAS score for upper arm pain was not significantly correlated with the T2 relaxation times, but was positively correlated with the T2 ratio.Conclusions: In patients with cervical radiculopathy, the SHINKEI-Quant technique can be used to quantitatively evaluate the compressed cervical nerve roots. The VAS score for upper arm pain was positively correlated with the T2 ratio. This suggests that the SHINKEI-Quant is a potential tool for the diagnosis of cervical nerve entrapment.