Previous research indicated that black and yellow leaf spots on Cymbidium, Ondontioda, Dendrobium... more Previous research indicated that black and yellow leaf spots on Cymbidium, Ondontioda, Dendrobium and Cattleya could be caused by Fusarium proliferatum worldwide. However, the agent causing leaf spot on Cymbidium spp. plants is still obscure in Taiwan. Thirty‐five F. fujikuroi species complex (FFSC)‐like isolates were collected from Cymbidium leaf spot from different greenhouses in Taiwan. All isolates were identified as F. proliferatum based on morphological characteristics and molecular analysis. Sequence of translation elongation factor 1‐alpha gene showed 99%–100% homology with F. proliferatum. In addition, two assay techniques using either detached leaves or seedlings were used to evaluate the pathogenicity and host range of the isolates and consequently their effects on Cymbidium and other orchid plants. Pathogenicity assays revealed that all isolates induced black and necrotic spots on detached leaves of Cymbidium, showing 9.4%–29.5% severity on seedlings of Cymbidium. Results of host specificity tests on detached leaves of different plants indicated that the F. proliferatum isolates collected from Cymbidium plants caused severe black spots on Oncidium, Cymbidium, Dendrobium and Cattleya plants. The symptoms on Phalaenopsis plants were relatively mild. Results of host specificity tests on plant seedlings indicated that the F. proliferatum isolates of Cymbidium origin were also pathogenic to Oncidium, Cymbidium and Dendrobium, but not to Cattleya and Phalaenopsis. Phylogenetic analysis of the translation elongation factor (TEF) gene among all fungal isolates using maximum parsimony (MP) and Bayesian inference (BI) methods revealed that the isolates of F. proliferatum from Cymbidium spp. could be separated from other FFSC‐like species with high phylogenetic support
In the field studies undertaken in central and southern Taiwan during 2003 to 2007, over 250 rust... more In the field studies undertaken in central and southern Taiwan during 2003 to 2007, over 250 rust specimens were collected. Among these specimens, Nyssopsora thwaitesii on Schefflera arboricola (Araliaceae), Goplana dioscoreae on Dioscorea sp. (Dioscoreaceae), Puccinia fusispora on Urtica thunbergiana (Urticaceae), P. paullula on Raphidophora sp. (Araceae) and Pucciniastrum potentillae on Fragaria hayatai (Rosaceae) were found as new geographic distribution records.
ABSTRACT Accurate taxonomic identification provides the foundation for a number of diatom applica... more ABSTRACT Accurate taxonomic identification provides the foundation for a number of diatom applications, such as the ecological monitoring of waters and the reconstruction of past environments. Despite significant recent developments in diatom taxonomy and phylogenetics, to date, only a few taxa have been studied extensively using a wide range of techniques. In this paper, data gained from intensive research on the morphology of live and cleaned diatom cells of two Fistulifera saprophila (Lange-Bertalot & Bonik) Lange-Bertalot strains isolated from the Gulf of Gdańsk are discussed. This study suggests that because specimens of F. saprophila have very delicate frustules prone to dissolution, the species has not been fully investigated and, therefore, a revised description is presented. Data on live cells and colony morphology, as well as interesting findings on the discrepancies between measurements of wet-mounted, dried and Naphrax-mounted diatom cells are also shown. The geographical distribution and ecological tolerance of F. saprophila is probably much wider than previously reported, but needs further investigation. The results of molecular phylogenetic analyses confirm the clear separation of Fistulifera Lange-Bertalot from Navicula Bory, also showing that its sister genera are Craticula Grunow, Eolimna Lange-Bertalot and Stauroneis Ehrenberg. Surprisingly, genera considered to have similar morphological characteristics, such as Mayamaea Lange-Bertalot and Sellaphora Mereschkowsky fall on a separate phylogenetic branch.
Mango (Mangifera indica L.) is an economically important tropical fruit in southern Taiwan. In Fe... more Mango (Mangifera indica L.) is an economically important tropical fruit in southern Taiwan. In February 2019, new leaf blotches distinct from anthracnose lesions were noticed on mango leaves in Meinong, Kaohsiung (N22°54'43.7" E120°32'59.3"). Symptoms were circular to irregular lesions with easily torn centers and were cream to light brown with dark brown margin on both leaf surfaces. Similar symptoms were observed on mango leaves in Yujing, Tainan (N23°07'31.3" E120°27'18.2") in July of the same year. We surveyed the disease incidence on 60 mango trees consisting of three cultivars, ‘Irwin’, ‘Yu-win No.6’ and a native cultivar in a commercial farm by randomly examining five shoots of each tree. The disease incidences of ‘Irwin’, the native cultivar and ‘Yu-win No.6’ were 25%, 37% and 73%, respectively. Diseased tissues from the two locations were surface sterilized and incubated on potato dextrose agar (PDA) for pathogen isolation. Seven isolates...
Abstract This study employed HPLC–PDA–ESI–MS analysis to characterize the mechanisms underlying t... more Abstract This study employed HPLC–PDA–ESI–MS analysis to characterize the mechanisms underlying the degradation of ethyl violet dyes. A nanostructural ZnO film was fabricated on the surface of the Zn foil of Alkaline-Manganese dioxide–Zinc Cells through a simple oxidation reaction in aqueous solution at room temperature. Our results indicate that the ZnO nanostructure/Zn-foil has outstanding potential for future applications in the photocatalytic degradation of organic dyes. The nanostructural polycrystalline ZnO was characterized using XRD, SEM, and XPS. To identify the underlying mechanism involved in ZnO/Zn-assisted degradation of EV dye, we separated and characterized 26 intermediates using HPLC–PDA–ESI–MS and GC–MS. Specifics related to the quantities of the intermediates provide an indication of possible degradation pathways associated with the decolorization of EV dyes.
Previous research indicated that black and yellow leaf spots on Cymbidium, Ondontioda, Dendrobium... more Previous research indicated that black and yellow leaf spots on Cymbidium, Ondontioda, Dendrobium and Cattleya could be caused by Fusarium proliferatum worldwide. However, the agent causing leaf spot on Cymbidium spp. plants is still obscure in Taiwan. Thirty‐five F. fujikuroi species complex (FFSC)‐like isolates were collected from Cymbidium leaf spot from different greenhouses in Taiwan. All isolates were identified as F. proliferatum based on morphological characteristics and molecular analysis. Sequence of translation elongation factor 1‐alpha gene showed 99%–100% homology with F. proliferatum. In addition, two assay techniques using either detached leaves or seedlings were used to evaluate the pathogenicity and host range of the isolates and consequently their effects on Cymbidium and other orchid plants. Pathogenicity assays revealed that all isolates induced black and necrotic spots on detached leaves of Cymbidium, showing 9.4%–29.5% severity on seedlings of Cymbidium. Results of host specificity tests on detached leaves of different plants indicated that the F. proliferatum isolates collected from Cymbidium plants caused severe black spots on Oncidium, Cymbidium, Dendrobium and Cattleya plants. The symptoms on Phalaenopsis plants were relatively mild. Results of host specificity tests on plant seedlings indicated that the F. proliferatum isolates of Cymbidium origin were also pathogenic to Oncidium, Cymbidium and Dendrobium, but not to Cattleya and Phalaenopsis. Phylogenetic analysis of the translation elongation factor (TEF) gene among all fungal isolates using maximum parsimony (MP) and Bayesian inference (BI) methods revealed that the isolates of F. proliferatum from Cymbidium spp. could be separated from other FFSC‐like species with high phylogenetic support
In the field studies undertaken in central and southern Taiwan during 2003 to 2007, over 250 rust... more In the field studies undertaken in central and southern Taiwan during 2003 to 2007, over 250 rust specimens were collected. Among these specimens, Nyssopsora thwaitesii on Schefflera arboricola (Araliaceae), Goplana dioscoreae on Dioscorea sp. (Dioscoreaceae), Puccinia fusispora on Urtica thunbergiana (Urticaceae), P. paullula on Raphidophora sp. (Araceae) and Pucciniastrum potentillae on Fragaria hayatai (Rosaceae) were found as new geographic distribution records.
ABSTRACT Accurate taxonomic identification provides the foundation for a number of diatom applica... more ABSTRACT Accurate taxonomic identification provides the foundation for a number of diatom applications, such as the ecological monitoring of waters and the reconstruction of past environments. Despite significant recent developments in diatom taxonomy and phylogenetics, to date, only a few taxa have been studied extensively using a wide range of techniques. In this paper, data gained from intensive research on the morphology of live and cleaned diatom cells of two Fistulifera saprophila (Lange-Bertalot & Bonik) Lange-Bertalot strains isolated from the Gulf of Gdańsk are discussed. This study suggests that because specimens of F. saprophila have very delicate frustules prone to dissolution, the species has not been fully investigated and, therefore, a revised description is presented. Data on live cells and colony morphology, as well as interesting findings on the discrepancies between measurements of wet-mounted, dried and Naphrax-mounted diatom cells are also shown. The geographical distribution and ecological tolerance of F. saprophila is probably much wider than previously reported, but needs further investigation. The results of molecular phylogenetic analyses confirm the clear separation of Fistulifera Lange-Bertalot from Navicula Bory, also showing that its sister genera are Craticula Grunow, Eolimna Lange-Bertalot and Stauroneis Ehrenberg. Surprisingly, genera considered to have similar morphological characteristics, such as Mayamaea Lange-Bertalot and Sellaphora Mereschkowsky fall on a separate phylogenetic branch.
Mango (Mangifera indica L.) is an economically important tropical fruit in southern Taiwan. In Fe... more Mango (Mangifera indica L.) is an economically important tropical fruit in southern Taiwan. In February 2019, new leaf blotches distinct from anthracnose lesions were noticed on mango leaves in Meinong, Kaohsiung (N22°54'43.7" E120°32'59.3"). Symptoms were circular to irregular lesions with easily torn centers and were cream to light brown with dark brown margin on both leaf surfaces. Similar symptoms were observed on mango leaves in Yujing, Tainan (N23°07'31.3" E120°27'18.2") in July of the same year. We surveyed the disease incidence on 60 mango trees consisting of three cultivars, ‘Irwin’, ‘Yu-win No.6’ and a native cultivar in a commercial farm by randomly examining five shoots of each tree. The disease incidences of ‘Irwin’, the native cultivar and ‘Yu-win No.6’ were 25%, 37% and 73%, respectively. Diseased tissues from the two locations were surface sterilized and incubated on potato dextrose agar (PDA) for pathogen isolation. Seven isolates...
Abstract This study employed HPLC–PDA–ESI–MS analysis to characterize the mechanisms underlying t... more Abstract This study employed HPLC–PDA–ESI–MS analysis to characterize the mechanisms underlying the degradation of ethyl violet dyes. A nanostructural ZnO film was fabricated on the surface of the Zn foil of Alkaline-Manganese dioxide–Zinc Cells through a simple oxidation reaction in aqueous solution at room temperature. Our results indicate that the ZnO nanostructure/Zn-foil has outstanding potential for future applications in the photocatalytic degradation of organic dyes. The nanostructural polycrystalline ZnO was characterized using XRD, SEM, and XPS. To identify the underlying mechanism involved in ZnO/Zn-assisted degradation of EV dye, we separated and characterized 26 intermediates using HPLC–PDA–ESI–MS and GC–MS. Specifics related to the quantities of the intermediates provide an indication of possible degradation pathways associated with the decolorization of EV dyes.
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Papers by Wen-Hsin Chung