• Title/Summary/Keyword: diseases and insects

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Molecular Mechanism of Plant Growth Promotion and Induced Systemic Resistance to Tobacco Mosaic Virus by Bacillus spp.

  • Wang, Shuai;Wu, Huijun;Qiao, Junqing;Ma, Lingli;Liu, Jun;Xia, Yanfei;Gao, Xuewen
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1250-1258
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    • 2009
  • Bacillus spp., as a type of plant growth-promoting rhizobacteria (PGPR), were studied with regards promoting plant growth and inducing plant systemic resistance. The results of greenhouse experiments with tobacco plants demonstrated that treatment with the Bacillus spp. significantly enhanced the plant height and fresh weight, while clearly lowering the disease severity rating of the tobacco mosaic virus (TMV) at 28 days post-inoculation (dpi). The TMV accumulation in the young non-inoculated leaves was remarkably lower for all the plants treated with the Bacillus spp. An RT-PCR analysis of the signaling regulatory genes Coil and NPR1, and defense genes PR-1a and PR-1b, in the tobacco treated with the Bacillus spp. revealed an association with enhancing the systemic resistance of tobacco to TMV. A further analysis of two expansin genes that regulate plant cell growth, NtEXP2 and NtEXP6, also verified a concomitant growth promotion in the roots and leaves of the tobacco responding to the Bacillus spp.

Expression of $HpaG_{Xooc}$ Protein in Bacillus subtilis and its Biological Functions

  • Wu, Huijun;Wang, Shuai;Qiao, Junqing;Liu, Jun;Zhan, Jiang;Gao, Xuewen
    • Journal of Microbiology and Biotechnology
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    • v.19 no.2
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    • pp.194-203
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    • 2009
  • $HpaG_{Xooc}$, from rice pathogenic bacterium Xanthomonas oryzae pv. oryzicola, is a member of the harpin group of proteins, eliciting hypersensitive cell death in non-host plants, inducing disease and insect resistance in plants, and enhancing plant growth. To express and secret the $HpaG_{Xooc}$ protein in Bacillus subtilis, we constructed a recombinant expression vector pM43HF with stronger promoter P43 and signal peptide element nprB. The SDS-PAGE and Western blot analysis demonstrated the expression of the protein $HpaG_{Xooc}$ in B. subtilis. The ELISA analysis determined the optimum condition for $HpaG_{Xooc}$ expression in B. subtilis WBHF. The biological function analysis indicated that the protein $HpaG_{Xooc}$ from B. subtilis WBHF elicits hypersensitive response(HR) and enhances the growth of tobacco. The results of RT-PCR analysis revealed that $HpaG_{Xooc}$ induces expression of the pathogenesis-related genes PR-1a and PR-1b in plant defense response.

A Greenhouse, Diseases and Insects Monitoring System based on PDA for Mobile Users (모바일 사용자를 위한 PDA 기반의 온실 및 병해충 모니터링 시스템)

  • Sim, Chun-Bo;Lim, Eun-Cheon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.12
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    • pp.2315-2322
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    • 2008
  • The requesting a consultation of the farm manager is about the diagnosis and prevention of the breeding and extermination for diseases and insects in greenhouse, the managing problem for diseases and insects turn up a main issue. To solve these problems, this paper proposes a PDA based greenhouse, diseases and insects management system for mobile(GDIMS) uses as keeping up with ubiquitous time, which makes prediction and management for diseases and insects more efficiently checked at any time and anywhere you want to, and go well with the motto of ubiquitous. This system is using the environmental data from the greenhouse attached sensors provide the accurate diagnosis and recipes, which supports to product clean crops. There are no need to visit the greenhouse because our system is based on mobile devices that obtain the information in the greenhouse, which makes management in efficient with little number of people. This wort builds simply virtual greenhouse model that assembles system component of environmental sensor for performance analysis and offers a PDA view of the greenhouse status.

Control of Diseases and Insects for Pesticide-free Cultivation of Leafy Vegetables (엽채류 유기재배의 병해충 관리)

  • Seo, Young-Ho;Cho, Byoung-Ouk;Choi, Jun-Keun;Kang, An-Seok;Jeong, Byung-Chan
    • Korean Journal of Organic Agriculture
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    • v.17 no.2
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    • pp.253-264
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    • 2009
  • This study was conducted to establish agricultural practices to control diseases and insects for chemical pesticide-free cultivation of leafy vegetables. Two diseases, gray mold(Botrytis cinerea) and soft rot(Erwinia carotovora), on lettuce were reduced by controlling temperature and humidity using air-circulation fan. The aphidophagous lady beetle(Harmonia axyridis) and primary parasitoids(Aphidius colemani) showed activity to control aphids density on Chinese cabbage. Co-application of cooking oil and yolk mixture (COY) and BT(Bacillus thuringiensis) decreased diseases including soft rot(Erwinia carotovora), downy mildew(Peronospora brassicae Gaumann), and powdery mildew(Eryslphe polygoni), and insects such as diamondback moth(Plutella xylostella) and beet armyworm(Spodoptera exigua Hubner). Neem extract treatment reduced downy mildew(Peronospora destructor) on Welsh onion.

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A Real-Time PCR Assay for the Quantitative Detection of Ralstonia solanacearum in Horticultural Soil and Plant Tissues

  • Chen, Yun;Zhang, Wen-Zhi;Liu, Xin;Ma, Zhong-Hua;Li, Bo;Allen, Caitilyn;Guo, Jian-Hua
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.193-201
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    • 2010
  • A specific and rapid real-time PCR assay for detecting Ralstonia solanacearum in horticultural soil and plant tissues was developed in this study. The specific primers RSF/RSR were designed based on the upstream region of the UDP-3-O-acyl-GlcNAc deacetylase gene from R. solanacearum, and a PCR product of 159 bp was amplified specifically from 28 strains of R. solanacearum, which represent all genetically diverse AluI types and all 6 biovars, but not from any other nontarget species. The detection limit of $10^2\;CFU/g$ tomato stem and horticultural soil was achieved in this real-time PCR assay. The high sensitivity and specificity observed with field samples as well as with artificially infected samples suggested that this method might be a useful tool for detection and quantification of R. solanacearum in precise forecast and diagnosis.

Growth Performance and Adaptability of Three-year-old Poplar and Willow Clones in a Riparian Area (하천연변에서 3년생 포플러 및 버드나무 클론의 생육특성 및 적응능력)

  • Yeo, Jin-Kie;Woo, Kwan-Soo;Koo, Yeong-Bon;Kim, Yeong-Sik
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.5
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    • pp.40-50
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    • 2007
  • One-year-old rooted cuttings of ten poplar clones and one willow clone were planted in a riparian area in Osan. Survival rate, growth performance, biomass, vitality, defoliation, leaf damages by diseases and/or insects and stem borer damage of the poplar and willow clones have been investigated for three growing seasons. Average survival rate of all eleven clones was declined from 80.7% for the first year to 60.7% for the third year. At three years after planting, poplar clones Dorskamp, ST-148 and Eco-28 showed the best survival rate of 80%. For height and DBH growth, the poplar clone Ay-48 and the willow clone 131-25 were the highest 8.3m and 9.5cm, respectively. However, poplar clones 72-30 and 72-31 were lower than those of the other clones. Clones Ay-48 and 131-25 seemed to have strong vitality when compare to the other clones. No serious damages by diseases and insects were found in most clones. Clones Ay-48 and ST-148 were the most tolerant to various diseases and insects. Clone Ay-48 produced the largest biomass for individual and annual total biomass, 22.5kg and 18.7ton $ha^{-1}$, respectively. Clone Dorskamp showed the best adaptability, which was estimated with survival rate, biomass and damages by various diseases and insects in the riparian area and followed by clones Ay-48, 97-19 and Eco-28. As a consequence, the four clones seemed to be the best candidate poplar clones for the establishment of riparian woody buffer.

Occurrence status of cone insects on Korean fir (Abies koreana) in Mt. Halla (한라산 구상나무 구과 해충 발생 현황)

  • Kim, Dosung;Lee, Yeong Don;Jwa, Myung Eun;Lee, Cha Young;Nam, Youngwoo
    • Korean journal of applied entomology
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    • v.59 no.4
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    • pp.417-420
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    • 2020
  • In this study, to grasp the current status of cone insects occurrence on Korean fir (Abies koreana) in Mt. Halla, 117 cones damaged by cone insects in three areas in Mt. Halla were collected and placed in growth chamber until adults emerged from the cones from August to October on 2019. And species and numbers of adults emerged from the cones were identified. Also proportion of cones damaged by cone insects was examined at four study plots in Mt. Halla. As a result, total 233, 101, and 4 adults of Dioryctria abietella (Denis & Schiffermüller), Cydia kamijoi Oku, and Scathophaga stercoraria (L.) were identified from 117 collected cones, respectively. The average number of emerged adults per cone was 1.99 for D. abietella and 0.86 for C. kamijoi. And the average damage rate of cone insects in four study plots of Mt. Halla ranged from 49.7-80.1 percent, with differences between regions. Also, our results show that positive correlation between the damage rate per tree and the number of cones per tree, and between number of emerged cone insects and the size of cones were found. It suggests that the cone insects prefer host trees with lots of cones per tree and with larger size of cones.

The present knowledge of farmers on pests and chemical control in grapevine culture (포도농가의 병해충 인식 및 화학적 방제 실태)

  • Cha, Byeong-Jin;Lee, Yun-Sang;Lee, Hyung-Rae
    • The Korean Journal of Pesticide Science
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    • v.4 no.1
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    • pp.38-43
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    • 2000
  • As the first step of a research on the establishment of control strategy for grapevine diseases and insects, the current status of pest control and yield losses by them were surveyed from grapevine growers of Korea. For insects, the most difficult to control was a grapevine stem borer and a grapevine clearwing moth was the next. On the other hand, several diseases including anthracnose, downy mildew, powdery mildew, bird's eye rot, leaf blight, were answered by the growers. The occurrence of the pests varied to the cultural practices. Yield loss was more serious in rainfall intercept culture than in plastic film house culture and diseases caused more loss in yield than insects did. However, the grapevine grower's potential for the identification of the kinds of pests was not high enough. When the pest was observed, the growers consulted mainly with local pesticide dealers or neighbouring growers and usually applied the pesticides prescribed by the dealer. More than half of the growers did not use pest control calendar, and most of the growers applied pesticides before any symptom appeared. Also, more than half of the growers applied mixture of at least more than 1 kind of pesticide and nutrients. Insecticides were applied less than 5 times during the season, but it was more than 6 times for fungicides. In the pesticide selection, the growers checked control effect first, regardless of the registration, and the pest control cost per unit area varied very much depending on the growers.

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Simultaneous detection of fungal, bacterial, and viral pathogens in insects by multiplex PCR and capillary electrophoresis

  • Kwak, Kyu-Won;Nam, Sung-Hee;Choi, Ji-Young;Lee, Seokhyun;Kim, Hong Geun;Kim, Sung-Hyun;Park, Kwan-Ho;Han, Myung-Sae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.30 no.2
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    • pp.64-74
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    • 2015
  • Beetles Protaetia brevitarsis seulensis Kolbe (Coleoptera: Cetoniidae) and Allomyrina dichotoma Linn. (Coleoptera: Scarabaeidae) are widely used in traditional medicine, and the number of insect-rearing farms is increasing in South Korea. The purpose of this study was to establish a multiplex PCR-based assay for rapid simultaneous detection of multiple pathogens causing insect diseases. Six insect parasites such as fungi Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (Metschn.) Sorokin (Hypocreales: Clavicipitaceae), bacteria Bacillus thuringiensis Berliner (Bacillales: Bacillaceae), Pseudomonas aeruginosa Migula (Pseudomonadales: Pseudomonadaceae), and Serratia marcescens Bizio (Enterobacteriales: Enterobacteriaceae), and Oryctes rhinoceros nudivirus were chosen based on the severity and incidence rate of insect diseases in South Korea. Pathogen-specific primers were designed and successfully applied for simultaneous detection of multiple infectious agents in farm-bred insects P. b. seulensis and A. dichotoma using multiplex PCR and high resolution capillary electrophoresis. Our results indicate that multiplex PCR is an effective and time-saving method for simultaneous detection of multiple infections in insects, and the QIAxcel capillary electrophoresis system is useful for quantitative evaluation of the individual impact of each infectious agent on the severity of insect disease. The approach designed in this study can be utilized for rapid and accurate diagnostics of infection in insect farms.