• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.51.1-51.1
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• 2005

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.436-439
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• 2006

This study was carried out to obtain basic information for optimum storage method of leaf, stem and root of Angelica acutiloba Radix, which is being utilized as major cultivated herbal medicine materials, root of Angelica acutiloba was stored for 3 months in different packing materials and sealing methods, such as punched packing, sealing and vacuum packing. The results are summarized as follows. The loss in weight as influenced by packing materials and sealing degree was the lowest at vacuum packing and complete sealing condition with transparent polyethylene film. The ratio of root rot during the storage period was not significantly different between polyethylene films, but it was significantly different between sealing conditions. Therefore, vacuum packing and complete sealing with polyethylene film are desirable storage condition for Angelica acutiloba Radix.

• Journal of Ginseng Research
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• v.4 no.1
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• pp.104-120
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• 1980

The effects of temperature on transpiration, chlorophyll content, frequency and aperture of stomata, and leaf temperature of Panax ginseng were reviewed. Temperature changes of soil and air under spade roof were also reviewed. Growth responses of responses of ginseng plant at various temperature were assessed in relation to suseptibillity of ginseng plants. Reasonable management of ginseng fields was suggested based on the response of ginseng to various temperatures. Stomata frequency may be increased under high temperature during leaf$.$growing stage. Stomata aperture increased by high temperature but the increase of both frequency and aperture appears not enough for transpiration to overcome high temperature encountered during summer in most fields. Serial high temperature disorder, i.e high leaf temperature, chlorophyll loss, inhibition of photosynthesis, increased respiration and wilting might be alleviated by high humidity and abundant water supply to leaf. High air temperature which limits light transmission rate inside the shade roof, induces high soil temperature(optimum soil temperature 16∼18$^{\circ}C$) and both(especially the latter) are the principal factors to increase alternaria blight, anthracnose, early leaf fall, root rot and high missing rate of plant resulting in poor yield. High temperature disorder was lessen by abundant soil water(optimum 17∼21%) and could be decreased by lowering the content of availability of phosphorus and nitrogen in soil consequently resulting in less activity of microorganisms. Repeated plowing of fields during preparation seems to be effective for sterilization of pathogenic microoganisms by high soil temperature only on surface of soils. Low temperature damage appeared at thowing of soils and emergence stage of ginseng but reports were limited. Most limiting factor of yield appeared as physiological disorder and high pathogen activity due to high temperature during summer(about three months).

• The Plant Pathology Journal
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• v.20 no.1
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• pp.52-57
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• 2004

Sclerotinia sp. (isolate BWC98-105) causes stem blight and root rot in Leghum sp., and is presently being evaluated as a potential mycoherbicide for the control of Trifoliorium repens. Bioassays have shown that Sclerotinia sp. produces phytotoxic substance which is biologically active against T. repens. Two biologically active compounds, designated as compoundsI and II, were produced in vitro from the culture filtrate of BWC98-105 isolate Sclerotium sp. Compounds I and II were purified by means of liquid-liquid extraction and $C_{18}$ open column chromatography (300 ${\times}$ 30 mm, i.d). To determine the purity, the purified compounds were analyzed by RP-HPLC. The analytical RP-HPLC column was a TOSOH ODS-120T (150 ${\times}$ 4.6 mm i.d, Japan), of which the flow rate was set at 0.7 mL/min using the linear gradient solvent system initiated with 15 % methanol to 85 % methanol for 50 min with monitoring at 254 nm. Under these RP-HPLC conditions, compounds I and II eluted at 3.49 and 4.13 min, respectively. Compound II was found to be most potent and host specific. However, compound I had a unique antibiotic activity against phytopathogenic bacteria like bacterial leaf blight (Xanthomonas oryzae) on rice, where it played a less important role in producing toxicity on T. repens. No toxin activity was detected in the water fraction after partitioning with several organic solvents. However, toxin activity was detected in the ethyl acetate and butanol fractions. In the leaf bioassay using compound II, the disease first appeared within 4-5 h as water soaked rot, which subsequently developed into well-defined blight affecting the whole plant.

• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.287-293
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• 1998

Bipolaris coicis, B. cynodontis, B. maydis and Curvularia lunata were leaf blight fungi detected from 45 seed samples of Job's tears and B. coicis was the predominant species in seed samples followed by C. lunata, B. cynodontis and B. maydis. When the seed components were plated on test tube agar, B. coicis and C. lunata were highly detected from invelucre, glume, endosperm and stamen, but not detected from plumule. Seed infection with B. coicis casued seed rot, coleoptile blight and seedling blight of Job's tears. Conidial characteristics of leaf blight fungi were as follows; B. cynodontis was fusiform, brown, slightly curved, 0~5 distoseptate, and 16.8-48$\times$7.2-16.8${\mu}{\textrm}{m}$ in size; B. cynodontis was fusiform, brown, slightly curved, 0~8 distoseptate, and 16.8-72$\times$9.6-19.2 ${\mu}{\textrm}{m}$; B. maydis was fusiform, brown, distintly curved, 0~10 distoseptate, and 28.8-110.4$\times$12-21.6 ${\mu}{\textrm}{m}$. C. Lunata was fusiform, brown, typically curved, 0~3 distoseptate, and 7.2-24$\times$4.8-12 ${\mu}{\textrm}{m}$. B. coicis was highly pathogenic to Job's tears and corn, weakly pathogenic to rice, but not pathogenic to wheat and barley. c. lunata was highly pathogenic to Job's tears (No. 2), corn, wheat and barley, weakly pathogenic to Job's tears (No. 1), but not pathogenic to rice. All treatments were effective to inhibition of leaf blight fungi when carboram, benoram, fludioxonil, prochloraz, thioram, and tap water treated to infected seeds.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.2
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• pp.101-106
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• 2007

During mulberry cultivation, root disease complex caused by the association of root knot nematode (Meloidogyne incognita) with root rot pathogens like Fusarium solani and Botryodiplodia theobromae poses serious loss in leaf production. Therefore, an attempt was made to assess the efficacy of eight pesticides (Metayalaxyl+Mancozeb, Thiophanate methyl, Mancozeb, Bitertanol, Phenomiphos, Phorate, Thionazin & Carbofuran) and two growth hormones (Salicylic acid and Indole 3 acetic acid) at 0.1 and 0.2% concentrations under in vitro conditions against nematode (hatching of eggs and mortality of larvae) and root rot pathogens (poisoned food technique) for short listing the treatments to develop an IDM strategy. Results revealed that among the pesticides and growth hormones, Carbofuran followed by Salicylic acid were found to be effective at 0.2% concentration against both nematode and pathogenic fungi. Both the chemicals inhibited the hatching of nematode eggs by 83.5-78.9% and 80-76% larval mortality over the control and reduced the mycelial growth of both the pathogenic fungi to an extent of 75.5-77.8%. Though Mancozeb inhibited both the pathogenic fungi strongly (77-80%), it did not show any effectiveness against nematode. The rest of the chemicals were found either moderately or poorly effective in reducing the growth of pathogenic fungi, hatching of nematode eggs and enhancing the mortality of larvae. The two effective chemicals viz., Carbofuran and Salicylic acid, which rated as strong inhibitors against both nematode and pathogenic fungi, can be exploited in developing an IDM package as one of the component for better management of root disease complex in mulberry.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.184-188
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• 2001

Phytophthora-induced diseases on citrus in Jeju island have been considered of minor importance because of the use as root stock of trifoliate orange, which is immune to Phytophthora. However, brown rot on fruit, which severely occurred in 1998 and 1999, has become a great threat to citrus production in the island. About one-half of the surveyed orchards were infected in 1998 and 4 out of 19 infected fields showed over 20% fruit infection rate. The disease was less severe in 1999, with an estimated infected area and total fruit reduction of 3,155 ha and 15,300 tons, respectively. Typical gummosis was also occasionally observed on cv. Shiranugi, which is mostly cultivated under plastic film houses. Two types of Phytophthora were consistently isolated from various plant parts, identified as P. citrophthora and P. nicotianae. The former was isolated from the aerial parts of the fruit, young leaf, and shoot in the fields. Meanwhile, the latter was only isolated from the basal stem showing gummosis in plastic film houses.

• The Plant Pathology Journal
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• v.25 no.1
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• pp.91-94
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• 2009

An unreported disease of garlic was observed in commercial fields in Jiangsu province, China. The symptoms started as water soaked lesions at the base of the leaves. Later, water-soaked areas developed on stems and spread to the internal tissues, followed by yellowing and necrosis along leaf edges and soft rot of the stems. The causal organism isolated from symptomatic plants was identified as Pseudomonas fluorescens based on its biochemical and physiological characteristics and confirmed by the cellular fatty acid composition and Biolog data as well as 168 rRNA gene sequence analysis. The bacterial isolates caused similar symptoms when inoculated onto garlic plants. In addition, leek and shallot were susceptible to the P. fluorescens pathogen. However, the P. fluorescens pathogen failed to cause any symptoms when it was inoculated onto 15 other plants. This is the first report of a bacterial disease of garlic caused by P. fluorescens in China.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1542-1550
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• 2016

This is the first report that paromomycin, an antibiotic derived from Streptomyces sp. AG-P 1441 (AG-P 1441), controlled Phytophthora blight and soft rot diseases caused by Phytophthora capsici and Pectobacterium carotovorum, respectively, in chili pepper (Capsicum annum L.). Chili pepper plants treated with paromomycin by foliar spray or soil drenching 7 days prior to inoculation with P. capsici zoospores showed significant (p < 0.05) reduction in disease severity (%) when compared with untreated control plants. The disease severity of Phytophthora blight was recorded as 8% and 50% for foliar spray and soil drench, respectively, at 1.0 ppm of paromomycin, compared with untreated control, where disease severity was 83% and 100% by foliar spray and soil drench, respectively. A greater reduction of soft rot lesion areas per leaf disk was observed in treated plants using paromomycin (1.0 μg/ml) by infiltration or soil drench in comparison with untreated control plants. Paromomycin treatment did not negatively affect the growth of chili pepper. Furthermore, the treatment slightly promoted growth; this growth was supported by increased chlorophyll content in paromomycin-treated chili pepper plants. Additionally, paromomycin likely induced resistance as confirmed by the expression of pathogenesis-related (PR) genes: PR-1, β-1,3-glucanase, chitinase, PR-4, peroxidase, and PR-10, which enhanced plant defense against P. capsici in chili pepper. This finding indicates that AG-P 1441 plays a role in pathogen resistance upon the activation of defense genes, by secretion of the plant resistance elicitor, paromomycin.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.646-650
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• 1998

Mycological characteristics of Phytophthora nicotianae var. nicotianae SPC10 (A1 type) causing Phytophthora rot of strawberry and the resistances of 11 strawberry cultivars against the pathogen were examined. Optimum temperature for the mycelial growth of the pathogen was obtained in the range of 30~35$^{\circ}C$, and the growth was completely stopped under 13$^{\circ}C$ or over 42$^{\circ}C$. Aerial mycelia were abundant on oatmeal agar (OMA), V-8 juice agar (V8A) and lima bean agar (LBA) medium, although there were slight differences, however, on cornmeal agar (CMA) medium, it was a shape of stellate without aerial mycelia. The colony shape on potato dextrose agar (PDA) medium was rough and irregular whereas the mycelial growth was slow, and some aerial mycelia were only produced in the middle of PDA medium. Optimum temperature for sporangial formation was 3$0^{\circ}C$, and zoospores were mostly released at $25^{\circ}C$ from the sporangia. Sporangia were more produced in C/Z solution with pH 5. 0~6.$0^{\circ}C$ than sterilized distilled water (DSW) and distilled water (DW), and zoospores were also released much more than other solutions. Eleven strawberry cultivars such as Reiko, Hokowase, Eyeberry, Akaneko, Sistakara, Toyonoka, Nyoho, Sulhong, Suhong, Myhong and Wonkyo #3104 revealed the disease incidence up to 88.9~100% by the leaf inoculation with mycelial disk. However, Nyoho and Suhong showed higher level of resistance against the pathogen by root inoculation.