Tsai J.-L.,National Chung Hsing University |
Tsuang B.-J.,National Chung Hsing University |
Kuo P.-H.,National Chung Hsing University |
Tu C.-Y.,Academia Sinica, Taiwan |
And 6 more authors.
Field measurements at various wetland ecosystems were conducted to investigate the coefficients b for different scalars in the relaxed eddy accumulation method. These measurements were performed at paddy, marsh and lagoon fields using the eddy covariance system to collect data with a sampling rate of 10 Hz. Without the application of a wind deadband, the mean median values of b were found to be 0.55 for paddy, 0.57 for marsh and 0.56 for lagoon for all scalar quantities under unstable and near-neutral conditions. However, the median values of b under stable conditions steadily increase with stability. The results of estimated b were well described by proposed relationships as a function of the dimensionless stability parameter z/L. Scalar similarity between carbon dioxide, temperature and water vapor showed a distinct diurnal pattern and change within the day where good scalar correlations were observed at paddy and marsh during daytime, but poor scalar correlations were observed at lagoon. With the application of wind deadband, the reductions of the normalized b factors, b REA, related to the increase of deadband values were evaluated and the results were compared with the reported relationships in the literature. The relative minimal variability of the normalized b REA was found when the wind deadband was equal to 0.8. From the diurnal variation of b REA, the relative maximum values of b REA factors occurred around noon, and lower values were observed in the early morning and late afternoon. Daily median b 0 values for various scalars under unstable and neutral conditions over paddy from the beginning to the end of the study period were used to verify the independence of the variations in surface roughness. © 2012 Elsevier Ltd. Source
Chen J.-J.,Tajen University |
Tsai C.-S.,Tajen University |
Hwang T.-L.,Chang Gung University |
Shieh P.-C.,Tajen University |
And 2 more authors.
Six new sesquiterpenes, curculonone A (1), curculonone B (2), curculonone C (3), curculonone D (4), 6α-hydroxycurcumanolide A (5), and 1,10-dehydro-10-deoxy-9-oxozedoarondiol (6), have been isolated from the rhizome of Curcuma longa, together with 19 known compounds. The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 2, 5, 12, 15, 16, and 23 exhibited inhibition (IC50 ≤ 18.22 μM) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 5, 12-16, and 23 inhibited fMLP/CB-induced elastase release with IC50 values ≤ 14.28 μM. © 2009 Elsevier Ltd. All rights reserved. Source
Chung C.-L.,National Taiwan University |
Huang S.-Y.,National Taiwan University |
Huang Y.-C.,National Taiwan University |
Tzean S.-S.,National Taiwan University |
And 9 more authors.
Since the 1990s, brown root rot caused by Phellinus noxius (Corner) Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR) regions in Daxi42 with the lowcoverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98%) of distinct multilocus genotypes (MLGs) and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s), which indicates that P. noxius may spread to adjacent trees via root-toroot contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan.We discuss the involvement of basidiospore dispersal in disease dissemination. © 2015 Chung et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source
Gale S.W.,Kochi Prefectural Makino Botanical Garden |
Maeda A.,Kochi Prefectural Makino Botanical Garden |
Chen C.-I.,Taitung District Agricultural Research and Extension Station |
Yukawa T.,Tsukuba Botanical Garden
Journal of Plant Research
An understanding of the extent to which reproductive strategy and seed dispersal lead to the structuring of genetic diversity in space is required when planning measures towards the conservation of endangered plant species. In this study, genetic structure in the endangered terrestrial orchid Nervilia nipponica was investigated using amplified fragment length polymorphisms following extensive sampling throughout the species' range in Japan and intensive sampling at a single population. Limited diversity was found within the species as a whole, but significant structuring was detected between populations. One genotype was common to two widely separated sites, possibly indicative of long-range dispersal. Significant structure was also detected at the intensively sampled site, as a result of the presence of two distinct putative clones. These findings are consistent with observations of the species' ability to set seed autogamously and propagate vegetatively. Given the strong colonising capability inferred for the species, attention should focus on identifying and securing habitat conditions conducive to seed germination and seedling establishment in the development of a conservation strategy. As presently circumscribed, N. nipponica is shown to comprise two polyphyletic taxa, both endemic to Japan, and both distinct from N. taiwaniana, a species that some authors have considered conspecific. © 2010 The Botanical Society of Japan and Springer. Source
Chen J.-J.,Tajen University |
Wang T.-C.,Tajen University |
Yang C.-K.,Tajen University |
Liao H.-R.,Chang Gung University |
And 5 more authors.
Chemistry and Biodiversity
Two new pterosin sesquiterpenes, (2S)-13-hydroxypterosin A (1) and (2S,3S)-12-hydroxypterosin Q (2), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D-NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 μg/ml) against Mycobacterium tuberculosis H37Rv in vitro. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich. Source