Entity

Time filter

Source Type


Kim K.M.,Chonbuk National University | Won G.Y.,Chonbuk National University | Choi I.Y.,Jeollabuk do Agricultural Research and Extension Services | Cho S.E.,Korea University | Shin H.D.,Korea University
Plant Disease | Year: 2016

Apple mint (Mentha suaveolens Ehrh., family Lamiaceae) is an herbaceous perennial plant that is most commonly grown as a culinary herb or for ground cover. In September 2014, dozens of apple mint plants in a plastic greenhouse in Namwon (35°26′02.3″ N; 127°32′58.4″ E), Korea, were found to be infected with a powdery mildew. Symptoms first appeared as circular to irregular white patches, which subsequently coalesced to develop into abundant hyphal growth on both sides of the leaves. As the disease developed, affected leaves became senescent and necrotic. A voucher specimen (KUS-F28392) was deposited in the Korea University Herbarium (KUS). Appressoria on the mycelium were nipple-shaped. Conidiophores were 70 to 170 × 9 to 11 μm and produced 2 to 5 immature conidia in chains with a sinuate outline. Foot-cells of the conidiophores were straight, cylindrical, slightly constricted at the base, and 36 to 60 μm long. Conidia were hyaline, ellipsoid to barrel-shaped, 26 to 40 × 16 to 22 μm (length/width ratio = 1.4 to 2.2), devoid of distinct fibrosin bodies, and showed reticulate wrinkling of the outer walls. Primary conidia were obconically rounded at the apex and subtruncate at the base. Germ tubes were produced at the perihilar position of conidia. No chasmothecia were observed until December. The structures were typical of the Euoidium anamorph of the genus Golovinomyces. The morphological characteristics were in agreement with those of G. biocellatus (Ehrenb.) V.P. Heluta (Braun and Cook 2012). To confirm the identification, molecular analysis of the sequence of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) of isolate KUS-F28392 was conducted. The complete ITS rDNA sequence was amplified using primers ITS1/ITS4, and sequenced. The resulting sequence was deposited in GenBank (Accession No. KT335972). A GenBank BLAST search of the Korean isolate sequence showed 100% identity with the ITS sequences of many G. biocellatus isolates on plants in the Lamiaceae (e.g., Accession Nos. HM156494, HM053470, AB307675, EU035602, etc.). Pathogenicity was confirmed by gently pressing a symptomatic leaf onto leaves of five healthy, potted apple mints. Five noninoculated plants served as controls. Plants were maintained in a greenhouse at room temperature. Inoculated plants developed symptoms after 8 days, whereas the control plants remained symptomless. The fungus present on inoculated plants was identical morphologically to that observed on the original diseased plants. Many species of Mentha have been recorded as host plants of G. biocellatus (Farr and Rossman 2015). Among them, G. biocellatus on Mentha suaveolens was recorded in Switzerland and Australia (Bolay 2005; Liberato and Cunnington 2007). To our knowledge, this is the first report of powdery mildew caused by G. biocellatus on M. suaveolens in Korea. Occurrence of powdery mildew on apple mint would be a potential threat to safe production of this herb. © The American Phytopathological Society.


Cho S.E.,Korea University | Zhao T.T.,Korea University | Choi I.Y.,Jeollabuk do Agricultural Research and Extension Services | Choi Y.J.,Kunsan National University | Shin H.D.,Korea University
Plant Disease | Year: 2016

Ramie (Boehmeria nivea (L.) Gaud.) (family Urticaceae) is a perennial herbaceous plant native to southeast Asia. It is widely cultivated throughout southeast Asian and Pacific Rim countries, especially China and India (Angelini and Tavarini 2013). In Korea, ramie is traditionally used to produce fibers for summer clothes, but also for its fresh leaves as a main ingredient of Moshiddeok, a green Korean rice cake, and Moshiguksu, a green Korean noodle (Park et al. 2014). In autumn 2015, ramie plants growing in shaded areas in Naju (35°02′49.7″ N; 126°42′39.3″ E), Korea, were observed to be infected with a powdery mildew with approximately 5% disease incidence. Powdery mildew colonies were circular to irregular or thinly effuse on both sides of the leaves and stems. Leaf withering or premature senescence, typical symptoms of powdery mildews, were not observed. A voucher specimen was deposited in the Korea University Herbarium (KUS). Appressoria on the hyphae were nipple-shaped or nearly absent. Conidiophores were straight, 90 to 200 × 11 to 13 μm, and produced 2 to 4 immature conidia in chains with a crenate outline. Foot-cells of conidiophores were cylindric and 40 to 70 μm long. Conidia were ellipsoid-ovoid to barrel-shaped, 25 to 38 × 16 to 23 μm with a length/width ratio of 1.5 to 2.0, and had distinct fibrosin bodies. Primary conidia were apically conical or rounded, mostly truncate at base, and generally smaller than secondary conidia. No chasmothecia were observed during the growing season. These structures are typical of the powdery mildew Euoidium anamorph of the genus Podosphaera. The morphological characteristics and measurements were consistent with those of P. xanthii (Castagne) U. Braun & Shishkoff (Braun and Cook 2012). To confirm the identification, the complete internal transcribed spacer (ITS) region of rDNA for an isolate KUS-F28930 was amplified with the primers ITS1/ITS4 and sequenced. The resulting 475-bp sequence was deposited in GenBank (Accession No. KU312040). A BLAST search of the Korean isolate showed 100% identity (475/475 bp) with the sequence of a P. xanthii isolate on Boehmeria nipononivea from Japan (AB026139). Pathogenicity was confirmed by dusting the conidia from a diseased leaf onto young leaves of three healthy ramie plants. Three noninoculated plants were used as control. Inoculated leaves developed signs similar to those observed on diseased leaves after 5 days, whereas the control plants remained healthy. Powdery mildew of Boehmeria spp. caused by a species of Podosphaera has been recorded in China, Japan, and Taiwan (Farr and Rossman 2015). To our knowledge, this is the first report of powdery mildew caused by P. xanthii on ramie in Korea. The incidence and economic cost of powdery mildew on ramie plants seem to be currently negligible, but the occurrence of this disease may threaten production of this crop in Korea, especially the availability of fresh leaves for moshiddeok and moshiguksu. © 2016 The American Phytopathological Society.


Lee J.-H.,Chonbuk National University | Kim D.-J.,Chonbuk National University | Ahn B.-K.,Jeollabuk do Agricultural Research and Extension Services
Bulletin of Environmental Contamination and Toxicology | Year: 2015

The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg-1. However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg-1. Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10 % to 8.20 % of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination. © 2015 Springer Science+Business Media New York.


Hong K.-J.,Plant and Fisheries Quarantine and Inspection Agency | Yu D.,Jeollabuk do Agricultural Research and Extension Services | Park S.,Seoul National University
Journal of Asia-Pacific Entomology | Year: 2012

The host plant, Schisandra chinensis (Turcz.) Baill. (Schisandraceae), of the weevil Dendrobaris maculata (Roelofs) (Madarini) is reported for the first time. The larvae grow in the lower stem of S. chinensis at the soil surface. Host plants are up to 5. years old. Redescription, photos of habitus, and genitalia of the weevil and damage and biological data of the host plant are provided. © 2011 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.


Kim D.-J.,Chonbuk National University | Shin H.-J.,Chonbuk National University | Ahn B.-K.,Jeollabuk do Agricultural Research and Extension Services | Lee J.-H.,Chonbuk National University
Applied Biological Chemistry | Year: 2016

This study was conducted to investigate thallium (Tl) adsorption in different soils, including acidic Jeonju (JJ), neutral Iksan (IS), and alkaline Danyang (DY) soils treated with various single counter metal ions and to examine the competitive adsorption of Tl with other metals, including cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn), in multicomponent systems. Thallium buffering capacity of the soils was ordered as IS > DY > JJ soil in the single-component systems, whereas it was DY > IS > JJ soil in the multicomponent systems. In the competitive systems of Tl with different single counter metals, the Tl adsorption capacity of the soils ranged from 20.33 to 88.38 and Tl bonding energy values ranged from 0.369 to 0.731. Thallium adsorption capacity and bonding energy were negatively correlated. Selectivity sequences of metals in multicomponent systems were Pb > Tl > Cu > Ni > Zn > Cd in the JJ soil, Pb > Cu > Tl > Zn > Cd > Ni in the IS soil, and Pb > Cu > Tl ≥ Zn > Cd > Ni in the DY soil. The metal buffering capacity in the JJ, IS, and DY soils varied from 293.2 to 1125.2. The values were ordered as Tl ≫ Pb ≥ Zn ≥ Ni > Cu ≥ Cd in the JJ soil, Pb > Cu > Tl ≫ Ni > Zn ≥ Cd in the IS soil, and Pb > Cu ≫ Tl > Ni > Cd ≥ Zn in the DY soil. © 2016 The Korean Society for Applied Biological Chemistry

Discover hidden collaborations