Motoyasu Minami

A New 14C Data Set of the PY608W-PC Sediment Core from Lake Pumoyum Co (Southeastern Tibetan Plateau) over the Last 19 kyr

A new continuous sediment core (PY608W-PC; 3.8 m length) for reconstruction of climatic and environmental changes in the southeastern Tibetan Plateau was taken from the eastern part of Lake Pumoyum Co in August 2006. Sediment layers of the lower part of PY608W-PC (380-300 cm depth) were composed mainly of relatively large plant residues (up to ~3 cm in length) with an admixture of fine sand and sandy silt. The large plant residues disappeared at ~300-290 cm depth in core PY608W-PC and were replaced by silt-silty clay. The large plant residues from the lower part of PY608W-PC could be aquatic, because the plant residues were extremely enriched in 13C (up to -3.0‰, -5.6 ± 2.3‰ on average). On the other hand, the plant residue concentrates (PRC fractions) from the upper part of the core (290-0 cm in depth) could be terrestrial C3 plants (?13C = -21.8 ± 1.7‰ on average). Radiocarbon dating was performed on the large plant residues and PRC fractions from the PY608W-PC sediment core, which represented the chronology from ~19,000 cal BP to present.

Preliminary survey of taxonomical problems, pharmacognostical characteristics, and chloroplast DNA polymorphisms of the folk medicinal herb Artemisia campestris from the Ryukyu Islands, Japan

Artemisia campestris L. (Compositae) occurs naturally along the coastline of the Ryukyu Islands and has been traditionally used as a folk medicine for the treatment of liver and kidney disorders. The authors obtained specimens from the Ishigaki and Kume Islands of the Ryukyu Islands, Japan, and from the USA. A survey of the literature revealed that the Japanese name for A. campestris is Niitaka-yomogi or Riukiu-yomogi. Two distinct overall plant-form phenotypes were identified: an erect phenotype with long, upright, and straight main axis and assurgent branches; and a prostrate phenotype, having branches that are longer than the main axis and which grow along the ground. Except for the number of ray flowers, most of the flower head characters in the erect phenotypes were significantly larger than those in the prostrate phenotypes. In this experiment, the flower heads contained only small amounts of either capillarisin (<0.01–0.11 of the dry weight, % DW) and 6,7-dimethylesculetin (<0.01–0.30% DW), or none at all. DNA polymorphisms at two sites of the rpl16–rpl14 spacer region (nucleotide position 181–189 and 291–300 from the 5′ end) revealed the existence of four different haplotypes. The number of adenines at nucleotide positions 291–300 appeared to be polymorphic within A. campestris from the Ryukyu Islands. Conversely, geographic differences between specimens from the Ryukyu Islands and USA manifested as a nine-base deletion at nucleotide positions 181–189. From a pharmacognostical context, the use of A. campestris flower heads as a substitute for Artemisiae capillaris Flos is not effective.

Identification of Muridae Species and Their Food Resources Using Dna Barcoding in Cat Tien National Park, Vietnam

Abstract. Field surveys of species in the family Muridae and their food resources were conducted in Cat Tien National Park, Vietnam in March 2011 and March and September 2012. Species were identified by DNA barcoding using polymorphic mitochondrial DNA sequences (COI, Cyt b, and D-loop) and external morphology. A total of four species, Maxomys surifer, Niviventer fulvescens, N. bukit, and Rattus sp. were identified. In order to identify which food resources were utilized by these species in the study area, total DNA was extracted from the gastric contents of the collected individuals. Sequence fragments of the chloroplast rbcL and the mitochondrial COI genes were amplified by PCR from the gastric contents and used to identify plant and animal food resources, respectively. We detected 34 plant families and seven animal orders by the homology search using the BLAST algorithm.

Evaluation of raw nepodin extraction from Rumex japonicus and R. obtusifolius and their DNA polymorphisms

Nepodin, found in the roots of Rumex japonicus Houtt. (Polygonaceae), inhibits osteoclast differentiation and has an antidiabetic effect. We propose nepodin as an ingredient of new functional foods or as a drug candidate for reducing the risk of reduced locomotion resulting from diseases such as osteoporosis. Although there are no previous reports of R. obtusifolius L., which is found throughout Japan, having roots containing nepodin, we found nepodin in the roots of this species. Therefore, R. obtusifolius as well as R. japonicus was considered a candidate raw material for nepodin extraction. We also discuss the suitability of R. japonicus and R. obtusifolius as sources of raw nepodin for cultivation on the Ryukyu Islands. In this study, all specimens on the Ryukyu Islands were identified as R. japonicus. Conversely, all specimens on mainland Japan were R. obtusifolius. The DNA sequence of the chloroplast trnL–trnF intergenic spacer region and partial nuclear internal transcribed spacer was consistent with the identification of R. japonicus and R. obtusifolius by morphological characteristics of the perianth segments. Therefore, to avoid erroneous identification and misuse of the plant species used for extraction of raw materials, it is preferable to develop DNA markers for these two regions. The content of nepodin varied from undetectable to 0.34% of the fresh weight (%FW) in R. japonicus and from undetectable to 0.21%FW in R. obtusifolius. From a pharmacological perspective, as plants that might be suitable as raw materials for nepodin extraction, it became clear that both R. japonicus and R. obtusifolius can be used with the same expected extraction efficiency. Based on our findings, R. obtusifolius could not be confirmed as inhabiting the Ryukyu Islands. For this reason, to conserve the endemic genetic characteristics of the Ryukyu Islands and to prevent genetic pollution by R. obtusifolius, only R. japonicus should be cultivated on the Ryukyu Islands.