Gyeongsangnam do Agricultural Research and Extension Services

Chinju, South Korea

Gyeongsangnam do Agricultural Research and Extension Services

Chinju, South Korea
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Hong S.H.,Korea University | Choi I.Y.,Jeollabuk do Agricultural Research and Extension Services | Kwon J.H.,Gyeongsangnam do Agricultural Research and Extension Services | Cho S.E.,Korea University | Shin H.D.,Korea University
Plant Disease | Year: 2017

Actinostemma lobatum Maxim. (Cucurbitaceae) is a climbing vine widely distributed in subtropical and temperate regions of Asia. It has been used for medicinal purposes, such as diuretic and antidote in Korea (Kim et al. 2008). Saponins are proposed to be the main bioactive components (Li et al. 2012). In August 2007, powdery mildew of the plants was first observed in natural ecosystems in Yangpyeong (37°32′16″N; 127°19′02″E), Korea. Signs first appeared as white colonies, which subsequently developed into abundant growth on both sides of the leaves. Symptoms included distortion and early defoliation of the leaves. Numerous chasmothecia were also formed on the leaves and stems in autumn. Powdery mildew on this plant has been found additionally in several localities in Korea. Five voucher specimens including 2016 collection have been deposited in the Korea University Herbarium (KUS). The hyphal appressoria were multilobed or moderately lobed. Conidiophores were straight, 70 to 120 × 7 to 9 µm, and composed of 3 to 4 cells. Foot-cells of conidiophores were straight or slightly flexuous at the base, and 25 to 35 µm long. Primary conidia were apically rounded and basally subtruncate. Conidia were oblong-elliptical, 31 to 42 × 15 to 21 µm with a length/width ratio of 1.6 to 2.5, devoid of distinct fibrosin bodies, and showed angular/rectangular wrinkling of outer walls. Germ tubes were produced in the perihilar position of the conidia. Chasmothecia were amphigenous, cauligenous, embedded in the mycelial mat, 80 to 130 μm in diameter, and contained 4 to 7 asci. Appendages were mycelioid, numerous, septate, and brown at the base. Asci were ellipsoid to obovoid, short-stalked, and 50 to 65 × 30 to 40 μm. Ascospores numbered 4 to 6 were ellipsoidal, 13 to 23 × 8 to 13 μm. The internal transcribed spacer (ITS) regions of KUS-F25657 selected for molecular identification were amplified with primers ITS1/ITS4, and sequenced directly. The resulting 674 bp sequence was deposited in GenBank (accession no. KY290257). A GenBank BLAST search of the Korean isolate showed >99% similarity with Erysiphe sp. on crassulaceous plants (e.g., EU185636 to EU185641). Therefore, the Korean isolate was determined to be an Erysiphe sp. Pathogenicity was confirmed through inoculation tests by gently pressing a diseased leaf onto three young leaves of three asymptomatic, potted plants. Three noninoculated plants were used as controls. Plants were maintained in a greenhouse at 24 to 30°C. Inoculated leaves developed symptoms 7 days after inoculation, whereas the control plants remained symptomless. Powdery mildews of A. lobatum have been recorded as E. actinostemmatis, E. pisi var. pisi, E. polygoni, and Golovinomyces cichoracearum from Japan and China (Amano 1986; Farr and Rossman 2016). However, the identity of the species of Erysiphe is still unclear and has to be proven and confirmed. To our knowledge, this is the first report of powdery mildew on A. lobatum in Korea. Common occurrence of the powdery mildew, especially in shady areas, can be a potential threat to the commercial cultivation of this medicinal vine in future. © 2017, American Phytopathological Society. All rights reserved.

Kwon J.-H.,Gyeongsangnam do Agricultural Research and Extension Services | Choi O.,Gyeongsang National University | Kim J.,Gyeongsang National University | Kwak Y.-S.,Gyeongsang National University
Journal of Phytopathology | Year: 2012

In the summers of 2010 and 2011, an anthracnose disease was observed on the Jatropha curcas L. grown at the research field of Gyeongsangnam-do Agricultural Research and Extension Services, South Korea. The symptoms included the appearance of dark brown spots on the leaf and fruit and the mummification of the fruit. The causal fungus formed grey to dark grey colony on potato dextrose agar. Conidia were single celled, ovoid or oblong, and 8-15×3-5μm in size while seta was dark brown, cone-shaped and 25-46×2-6μm in size. The optimum temperature for growth was approximately 30°C. On the basis of mycological characteristics, pathogenicity test and molecular identification using internal transcribed spacer rDNA sequence, the fungus was identified as Colletotrichum gloeosporioides. To our knowledge, this is the first report of an anthracnose caused by C. gloeosporioides on J. curcas plant in Korea. © 2012 Blackwell Verlag GmbH.

Kwon J.-H.,Gyeongsangnam do Agricultural Research and Extension Services | Kim J.,Gyeongsang National University | Kim W.-I.,South Korean National Institute of Animal Science
Mycobiology | Year: 2011

Soft rot in apple caused by Rhizopus oryzae was found for the first time in Korea. A detailed description of the specimen is given along with its internal transcribed spacer rDNA sequence. The fungus was identified as Rhizopus oryzae based on the mycological characteristics, molecular data, and pathogenicity testing. © The Korean Society of Mycology.

Hong M.J.,Dong - A University | Lee Y.M.,Dong - A University | Son Y.S.,Gyeongsang National University | Im C.H.,Gyeongsangnam do Agricultural Research and Extension Services | And 4 more authors.
Biochemical and Biophysical Research Communications | Year: 2013

Rab proteins play an essential role in regulating vesicular transport in eukaryotic cells. Previously, we characterized OsRab11, which in concert with OsGAP1 and OsGDI3 regulates vesicular trafficking from the trans-Golgi network (TGN) to the plasma membrane or vacuole. To further elucidate the physiological function of OsRab11 in plants, we performed yeast two-hybrid screens using OsRab11 as bait. OsOPR8 was isolated and shown to interact with OsRab11. A co-immunoprecipitation assay confirmed this interaction. The green fluorescent protein-OsOPR8 fusion product was targeted to the cytoplasm and peroxisomes of protoplasts from Arabidopsis thaliana. OsOPR8 exhibited NADPH-dependent reduction activity when 2-cyclohexen-1-one (CyHE) and 12-oxo-phytodienoic acid (OPDA) were supplied as possible substrates. Interestingly, NADPH oxidation by OsOPR8 was increased when wild-type OsRab11 or the constitutively active form of OsRab11 (Q78L) were included in the reaction mix, but not when the dominant negative form of OsRab11 (S28N) was included. OsRab11 was expressed broadly in plants and both OsRab11 and OsOPR8 were induced by jasmonic acid (JA) and elicitor treatments. Overexpressed OsRab11 transgenic plants showed resistance to pathogens through induced expression of JA-responsive genes. In conclusion, OsRab11 may be required for JA-mediated defense signaling by activating the reducing activity of OsOPR8. © 2013 Elsevier Inc.

Park S.,Gyeongsang National University | Jeong W.Y.,Gyeongsang National University | Lee J.H.,Gyeongsang National University | Kim Y.-H.,Gyeongsang National University | And 7 more authors.
Food Chemistry | Year: 2012

Healthy fruits of Capsicum annuum L. cv. Chelsea (yellow bell pepper) and one infected by Colletotrichum gloeosporioides were analysed for polyphenols via high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Among seven polyphenols characterized, four components in the C. annuum fruits were identified for the first time. To investigate the characteristics of the polyphenols as defence materials, the content change of the fruit polyphenols inoculated with C. gloeosporioides was monitored by HPLC. It was observed for the first time that de novo induced N-caffeoyl putrescine (1) and caffeoyl O-hexoside (2) appeared to act as a phytoalexin in the defence mechanism of the C. annuum fruits against C. gloeosporioides, and constitutively formed feruloyl O-glucoside (3), kaempferol O-pentosyldihexoside (4) and dihydroxyflavone O-hexoside (7) as a phytoanticipin in the diseased C. annuum fruits. © 2011 Published by Elsevier Ltd. All rights reserved.

Kwon J.-H.,Gyeongsangnam do Agricultural Research and Extension Services | Kang D.-W.,Gyeongsangnam do Agricultural Research and Extension Services | Kim S.-R.,Gyeongsangnam do Agricultural Research and Extension Services | Kim J.,Gyeongsang National University
Plant Disease | Year: 2016

Passion fruit (Passiflora edulis) is a vine species of passion flower that is native to Brazil, Paraguay, and northern Argentina. In South Korea, it is widely grown for its sweet and seedy fruit. In March 2014, passion fruit flowers with gray mold (approximately 50% incidence) were sampled from the exhibition field of the Agricultural Technology Service Center in Jinju, South Korea. Symptoms first appeared on flowers, which turned brown and then died, with masses of gray or brownish spores produced on infected tissues. No gray mold symptoms were observed on leaves, stems, or fruit. To isolate fungal pathogens, diseased flower tissues excised from the margins of lesions were surface-disinfested in 1% NaOCl for 10 s, rinsed three times with sterile distilled water, and placed on water agar and cultured at 25°C for 2 days. Mycelial tips of developing fungal cultures were transferred to potato dextrose agar (PDA) for identification. Five Botrytis isolates were recovered from the infected plant samples. All fungal colonies were gray brown and produced sclerotia on PDA. The conidia were one-celled, mostly ellipsoid or ovoid, and colorless or pale brown. The conidia were 6 to 19 × 4 to 12 μm (n = 50) and conidiophores were 15 to 33 μm long. Based on the morphological characteristics, the fungi were placed in the Botrytis cinerea group (Ellis and Waller 1974). To confirm the identity of the fungus, the complete internal transcribed spacer (ITS) rDNA region of a representative isolate MHGNU F114 was amplified using ITS1/ITS4 primers (White et al. 1990). The DNA products were cloned into the pGEM-T Easy vector (Promega, Madison, WI) and the resulting plasmid (pOR187) was sequenced using universal primers at Macrogen Services (Daejeon, South Korea). A BLASTn search of the ITS rDNA sequence of the isolate MHGNU F114 (GenBank Accession No. KU234690) confirmed the identity of the fungus; the sequence obtained was homologous and shared 99% identity with the B. cinerea isolate LGM002 from Brazil and clone GTB from Florida, causing gray mold on pea (KC683713) and German thyme (KT737373), respectively (Dallagnol et al. 2014). For further confirmation, two nuclear protein-coding genes were sequenced: heat-shock protein 60 (HSP60) and DNA-dependent RNA polymerase subunit II (RPB2) (Staats et al. 2005). The HSP60 and RPB2 sequences (KU760985 and KU760986) of the isolate were 99 to 100% identical to those of B. cinerea strains B05.10 and T4, respectively. Isolate MHGNU F114 was used to conduct pathogenicity tests on the flowers of two 1-year-old passion fruit plants grown in pots. Five flowers from one passion fruit plant were inoculated by spraying a conidial suspension of 3 × 105 conidia/ml until run-off. Five negative control flowers of another passion fruit plant were treated with sterilized distilled water. The two plants were stored in a moist chamber with >90% relative humidity at 25°C, and after 2 days the plants were placed in a greenhouse. Seven days after inoculation, gray mold symptoms similar to those observed in the field developed on the inoculated flowers, whereas the control flowers remained asymptomatic. B. cinerea was reisolated from the lesions of the inoculated flowers to fulfill Koch’s postulates. The morphological features of fungi reisolated from inoculated flowers were the same as those of the original isolates. To our knowledge, this is the first report of gray mold caused by B. cinerea on P. edulis in Korea. © 2016 The American Phytopathological Society.

Lee J.E.,Gyeongsang National University | Kim G.-S.,Gyeongsang National University | Park S.,Gyeongsang National University | Kim Y.-H.,Gyeongsang National University | And 6 more authors.
Food Chemistry | Year: 2014

The type and content of plant polyphenols can be influenced by maturity. Korean chokeberry (Aronia melanocarpa) leaves of three different maturities (young, mature, and aged) were extracted with 70% aqueous methanol. The polyphenols in the leaves were analysed for the first time using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and comparison with reported data. Among the 12 characterised components, five flavonoids, 3, 4, and 10-12, and a dicaffeoylquinic acid derivative, 6, were characterised for the first time in chokeberry leaves. Each polyphenol component was validated and quantified using a representative polyphenol standard of the same group. The antioxidant activity of the three different mature leaf extracts was determined. The antioxidant activity was highest for young leaves, followed by mature and aged leaves. The results suggest that younger chokeberry leaves may be more favourable for processing a higher quality functional tea due to their higher polyphenol content. © 2013 Elsevier Ltd. All rights reserved.

Lee J.H.,Gyeongsang National University | Lee S.J.,Gyeongsang National University | Park S.,Gyeongsang National University | Kim H.K.,Gyeongsang National University | And 7 more authors.
Food Chemistry | Year: 2011

Orostachys japonicus cultivated in the Republic of Korea was analysed for flavonoid content via HPLC coupled to MS/MS. Amongst 16 compounds that were characterised, eight flavonoids and one alkaloid were characterised for the first time: two procyanidin dimer gallate isomers (1 and 2), epigallochatechin-3-gallate (3), two procyanidin dimer digallate isomers (4 and 9), quercetin 3-O-rhamnosyl-7-O-glucoside (6), myricetin 3-O-glucoside (10), kaempferol (16) and N1,N5,N10-tri-p-(E,E,E)-coumaroylspermidine (15). The identified compounds were quantified by HPLC-UV/DAD. The antioxidant activity of the O. japonicus flavonoids was determined via 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS•+) and nitric oxide radical (NO•) scavenging assays. © 2010.

Choi O.,Gyeongsang National University | Kwak Y.-S.,Gyeongsang National University | Kim J.,Gyeongsang National University | Kwon J.-H.,Gyeongsangnam do Agricultural Research and Extension Services
Mycobiology | Year: 2012

The tulip tree (Liriodendron chinense) has been widely cultivated in Korea as a street or garden tree for its large flowers, which have a superficial resemblance to tulips. Occurrence of anthracnose disease on the leaves of tulip trees growing on the campus of Gyeongsang National University, Jinju, Korea, has been observed. Based on mycological characteristics, pathogenicity, and internal transcribed spacer sequence, the causal fungus was identified as Colletotrichum gloeosporioides. This is the first report on anthracnose disease caused by C. gloeosporioides on tulip trees in Korea. © The Korean Society of Mycology.

PubMed | CAS Yantai Institute of Coastal Zone Research, Gyeongsangnam Do Agricultural Research and Extension Services and Pusan National University
Type: Journal Article | Journal: Sensors (Basel, Switzerland) | Year: 2015

In this paper, we present a challenging task of 3D segmentation of individual plant leaves from occlusions in the complicated natural scene. Depth data of plant leaves is introduced to improve the robustness of plant leaf segmentation. The low cost RGB-D camera is utilized to capture depth and color image in fields. Mean shift clustering is applied to segment plant leaves in depth image. Plant leaves are extracted from the natural background by examining vegetation of the candidate segments produced by mean shift. Subsequently, individual leaves are segmented from occlusions by active contour models. Automatic initialization of the active contour models is implemented by calculating the center of divergence from the gradient vector field of depth image. The proposed segmentation scheme is tested through experiments under greenhouse conditions. The overall segmentation rate is 87.97% while segmentation rates for single and occluded leaves are 92.10% and 86.67%, respectively. Approximately half of the experimental results show segmentation rates of individual leaves higher than 90%. Nevertheless, the proposed method is able to segment individual leaves from heavy occlusions.

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