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Field validation of PBcast, an infection risk model for Phytophthora blight of pepper, was conducted through a designed field experiment in 2012 and 2013. Conduciveness of weather conditions at 26 locations in Korea in 2014-2017 was also evaluated using PBcast. The PBcast estimated daily infection risk (IR) of Phytophthora capsici based on weather and soil texture data. In the designed filed experiment, four treatments including routine sprays at 7-day intervals (RTN7), forecast-based sprays when IR reached 200 (IR200) and 224 (IR224), and no spray (CTRL) were compared in terms of disease incidence and number of sprays recommended for disease control. In 2012, IR had reached over 200 twice, but never reached 224. In 2013, IR had reached over 200 three times and once higher than 224. The RTN7 plots were sprayed 17 and 18 times in 2012 and 2013, respectively. Weather conditions throughout the country were generally conducive for Phytophthora blight and 3-4 times of fungicide sprays would have been reduced if the PBcast forecast information was adopted in the decision-making for fungicide sprays. In conclusion, the PBcast forecast would be useful to reduce fungicide applications without losing the disease control efficacy to protect pepper crop from Phytophthora blight.

To preventively control fire blight in apple trees and determine policies regarding field monitoring, the Maryblyt ver. 7.1 model (MARYBLYT) was evaluated in the cities of Chungju, Jecheon, and Eumseong in Korea from 2015 to 2020. The number of blossom infection alerts was the highest in 2020 and the lowest in 2017 and 2018. And the common feature of MARYBLYT blossom infection risks during the flowering period was that the time of BIR-High or BIR-Infection alerts was the same regardless of location. The flowering periods of the trees required to operate the model varied according to the year and geographic location. The model predicts the risk of “Infection” during the flowering periods, and recommends the appropriate times to control blossom infection. In 2020, when flower blight was severe, the difference between the expected date of blossom blight symptoms presented by MARYBLYT and the date of actual symptom detection was only 1-3 days, implying that MARYBLYT is highly accurate. As the model was originally developed based on data obtained from the eastern region of the United States, which has a climate similar to that of Korea, this model can be used in Korea. To improve field utilization, however, the entire flowering period of multiple apple varieties needs to be considered when the model is applied. MARYBLYT is believed to be a useful tool for determining when to control and monitor apple cultivation areas that suffer from serious fire blight problems.

수출입 검역에 사용하던 methyl-bromide (MtBr) 훈증제 대 안으로 감마선, 엑스선과 같은 이온화 에너지를 식물검역에 활용한 것은 1995년 미국 하와이에서 본토로 과실류 통관 이 시초였으며(Zhao 등, 1996), 이후 2004–2007년에 호주, 태 국, 인도, 파키스탄, 남아공 등에서 표준처리절차서(standard operating procedure, SOP)를 만들어 활용 중이다. 우리나라 에서도 방사선을 이용한 실용화 기술 개발을 통한 국가차원 검역관리 체계를 구축하고자 검역본부의 소독 기준 처리 설 정 및 표준처리절차 지침을 마련하기 위해 2013-2015년에 주요 수출 과채류(사과, 배, 단감, 감귤, 고구마, 파프리카)와 절화 화훼류(장미, 국화, 백합)에 이온화 에너지를 처리한 농 산물의 품질 평가를 실시하였다. 과채류는 대체로 400 Gy까 지는 무난하나, 조직이 얇고 연한 화훼류는 100–200 Gy의 저 선량도 품목에 따라 품질저하를 보이므로 한계흡수 선량 결 정에 신중하여야 한다. 이온화 에너지에 대한 장해와 저항성 차이는 같은 종이라

A population density model for bacterial wilt, which is caused by Ralstonia solanacearum, in hot pepper was developed to estimate the primary infection date after overwintering in the field. We developed the model mechansitically to predict reproduction of the pathogen and pathogensis on seedlings of the host. The model estimates the pathogen`s populations both in the soil and in the host. In order to quantify environmental infection factors, various temperatures and initial population densities were determined for wilt symptoms on the seedlings of hot pepper in a chamber. Once, the pathogens living in soil multiply up to 400 cells/g of soil, they can infect successfully in the host. Primary infection in a host was supposed to be started when the population of the pathogen were over cells/g of root tissue. The estimated primary infection dates of bacterial wilt in 2011 in Korea were mostly mid-July or late-July which were 10-15 days earlier than those in 2010. Two kinds of meterological data, synoptic observation and field measurements from paddy field and orchard in Kyunggi, were operated the model for comparing the result dates. About 1-3 days were earlier from field data than from synoptic observation.

Department of Biomedical Sciences, Sun Moon University, Asan 330-744, Korea (Received on July 18, 2011; Revised on August 19, 2011; Accepted on August 20, 2011)During 2002−2008 in Korea, 455 extracts from myxo-bacteria consisting of 318 cellulolytic and 137 bacterio-lytic myxobacteria were isolated, which were then screen-ed for antifungal activity against the phytopathogensBotrytis cinerea, Colletotrichum acutatum, Penicilliumsp., Pyricularia grisea, and Phytophthora capsici. 204isolates had antifungal activity, causing both a clearzone due to blocked spore germination and inhibitionof mycelial growth; most (199) were from cellulolytic(Sorangium cellulosum) and only five were from bac-teriolytic myxobacteria. B. cinerea, the best controlledamong the five tested pathogens, had a unique group ofantifungal isolates of myxobacterial extracts comparedto the other pathogens’ groups. Among seventy-ninebioactive myxobacteria, four isolates, KYC 3130, KYC3247, KYC 3248 and KYC 3270, were selected and allwere cellulolytic. Liquid culture filtrates of these fourmyxobacteria were applied to tomato, cherry tomato,strawberry, and kiwi fruits 5 h before inoculation withgray mold conidia; then the treated fruits were placedin an airtight container and the experiment was repeat-ed six to eight times. Incidence (%) of gray mold onfruit of the infected control treatment was 84−98%,whereas it was only 5−21% after the KYC 3270 treat-ment. After KYC 3270 treatment of the four fruits,mold control was 79−95%, which was highest amongthe filtrates and statistically the same as treatment withfludioxonil, a registered chemical against gray mold ofstored fruits. Keywords :antifungal activity, Botrytis cinerea, cellulolyticmyxobacteria, strawberryMyxobacteria have a fruiting body with bacteriolytic orcellulolytic characteristics (Cho, 2001; Dawid, 2000; Kimand Son, 2001; Kim et al., 2003a). The cellulolytic myxo-bacteria are able to degrade cellulose, grow well, and can beisolated in culture medium containing cellulose. So far, twospecies of cellulolytic myxobacteria are known, Sorangiumcellulosum and Byssovorax cruenta (Reichenbach, 2001).S. cellulosum produces more than 30 different bioactivemetabolites, including ambruticin, chivosalzole, disorazole,eliamid, epothilone, etnangien, jerangolid, ratjadon, socein,sorangicin, soraphen, spirodienal, spirangien, and tartrolon,which comprise 48% of the bioactive metabolites of myxo-bacteria (Dawid, 2000; Gerth et al., 2003; Niggemann et al.,2002).Most bioassays for biological activity of myxobacteriahave been with bacteriolytic myxobacteria such as Myxo-coccus spp. (Ahn and Kim, 2002; Bull et al., 2002; Chunget al., 2008; Kim and Yun, 2011; Kim et al., 1998; Kim etal., 2003b; Krug et al., 2008), although the antifungalactivity of S. cellulosum, a cellulolytic myxobacterium,against several phytopathogenic fungi has been examinedin Germany (Reichenbach and Hofle, 1994). Soraphen andepothilone are two natural products of S. cellulosum, andsoraphen in particular is an antifungal compound. In fieldtrials, this compound completely inhibited apple scab fungi(Venturia inaequalis) and also prevented grape gray mold(Botrytis cinerea) (Reichenbach and Hofle, 1994). Accord-ing to the paper disk method for dual culture, Spirodienal C,new metabolites from S. cellulosum, have antifungal activityagainst B. cinerea , Botryosphaeria dothideaand Sclerotiniasclerotiorum (Ahn, 2009). Hence, such a cellulolytic myxo-bacterium has extraordinary ability to produce secondarymetabolites with biological activity (Gerth, 2003); however,more cellulolytic myxobacteria containing similar naturalproducts have yet to be studied. B. cinerea is a phytopathogen on more than 200 speciesunder humid and low temperature conditions during storage(Hang et al., 2005; Kulakiotu et al., 2004; Tian et al., 2002;Williamson et al., 2007). To control B. cinerea in Koreanfields, many fungicides having different modes of actionwere developed, e.g., benzimidazole, dicarboximide, sulf-amide, N-phenylcarbamate, phenylpyrrol, and anilinopyri-midine (Choi et al., 1999, 2009a). However, A B. cinerearesistance to benzimidazole through a change of amino acidresidue in β-tubulin was discovered (Soung and Sung

Department of Biomedical Sciences, Sun Moon University, Asan 330-744, Korea (Received on February 16, 2011; Revised on April 9, 2011; Accepted on April 15, 2011)Bacteriolytic myxobacteria have been known to secrete various antifungal metabolites against several soil-borne phytopathogens including Phytophthora. Among the three isolates of Myxococcus spp., KYC 1126 andKYC 1136 perfectly inhibited the mycelial growth of Phytophtora capsici in vitro. In order to show thebiocontrol activity on Phytophthora blight of hot pepper, we tried to find the best way of application of amyxobacterial isolate. Although KYC 1126 fruiting body was easily grown on the colony of Escherichia coli asa nutrient source, it did not control the disease when it was pre-applied in soil. Before the bioassay of a liquidculture filtrate of KYC 1126 was conducted, its antifungal activity was confirmed on the seedlings applyingwith the mixture of the pathogen's zoospore suspension and KYC 1126 filtrate. On greenhouse experimentswith five and four replications, the control value of KYC 1126 on phyllosphere and rhizosphere was 88% and36%, respectively. Whereas, the control value of dimetnomorph+propineb on phyllosphere was 100% andthat of propamorcarb on rhizosphere was 44%. There was a phytotoxicity of the myxobacterial filtrate whenseedlings were washed and soaked for 24 hours. Gummy materials were covered with roots. And stem andpetiole were constricted, then a whole seedling was eventually blighted.Keywords : Antifungal metabolites, Bacteriolytic myxobacteria, Myxococcus, Phytophthora capsici

Department of Biomedical Sciences, Sun Moon University, Asan 330-744, Korea (Received on February 15, 2011; Accepted on March 31, 2011)Antifungal activity of three Myxococcus spp., KYC1126, 1136, and 2001, was tested in vitro against threephytopathogenic fungi (Botrytis cinerea, Colletotrichumacutatum, and Pyricularia grisea). Spore germinationand mycelial growth of the three pathogenic fungi werecompletely inhibited by bioactive substances from amyxobacterium KYC 1126. In addition, the activity ofKYC 1126 was fungicidal, but liquid culture filtrate ofKYC 1126 did not affect protoplast reversion in C.acutatum. A bioassay of KYC 1126 filtrate againstanthracnose in hot pepper was conducted in the green-house and field at 2009 and 2010. The incidence ofanthracnose in control seedlings was 74%, but wasreduced to 29% after KYC 1126 treatment. The controlvalue with KYC 1126 was 60% while that with thefungicide dithianon was 42%. In the greenhouse, diseaseincidence with KYC 1126 was consistentely 10−35%lower than with fungicide as a positive control. Thecontrol value with KYC 1126 was 13.4% and 41.0%,whereas that with the fungicide was 52.3% and 63% in2009 and 2010, respectively. Although anti-anthracnoseactivity of KYC 1126 was not maintained for long timein the field, the bacteriolytic myxobacterium KYC 1126could be a prospective biocontrol agent. Keywords : antifungal activity, biocontrol, Colletotrichumacutatum, myxobacteriaMyxobacteria are rod-shaped, Gram-negative unicellularsoil bacteria belonging to the proteobacteria δ group. Theycan produce lytic metabolites, move without flagella, andscavenge microbes by using biomacromolecules (Shimkets,1990). They are considered micropredators because theantibiotics and enzymes produced can kill other microbesand lyse macromolecules of dead microbes. Myxobacteriaare a rich source of bioactive secondary metabolites that arenot found in other antagonists such as pseudomonads andBacillus spp. and are being evaluated as a source of novelcompounds (Bull et al., 2002; Dawid, 2000; Gaspari et al.,2005; Gerth et al., 2003; Krug et al., 2008; Reichenbach,2001). In studies over more than 25 years, about 80 basicstructures and 350 variants have been identified. Most haveantifungal and anticancer activity in human disease (Kim etal., 2003). Myxobacteria are mainly bacteriolytic andcellulolytic. The bacteriolytic myxobacteria produce theagriculturally important antibiotic, pyrrolnitrin. The generaMyxococcus, Corallococcus , Cystobacter, Archangium, andStigmatella are bacteriolytic myxobacteria and are richsources of bioactive metabolites including aurachin, corallo-pyronin, crocacin, myxalamid, myxochelin, myxothiazol,myxovirescin, pyrrolnitrin, saframycin, and stigmatellin(Bartlett et al., 2002; Dawid, 2000; Kim et al., 2003; Kruget al., 2008; Reichenbach, 2001; Wang and Tao, 2009).Anthracnose is the most destructive disease of hot pepper,and attempts have been made to control it biologicallyusing Bacillus sp. (Park et al., 2006), Gliocladium virens(Jang et al., 2001), Pantoea agglomerans (Jung et al.,2007), Pseudomonas koreansis (Kim et al., 2007), Strepto-myces griseofuscus (Lim, 2005), B. subtilis, G. roseum, S.natalensis , S. noursei, and Trichoderma harzianum (Žvkoviet al., 2010) as antagonists. In contrast to the listed anta-gonists to anthracnose, the use of secondary metabolitesfrom myxobacteria in the interaction of anthracnose withhot pepper has not been explored. As a new and novelbiological control for anthracnose, myxobacteria antibioticsand cell wall degrading enzymes are worth developing(Shimkets, 1990). Some studies have evaluated myxobacteria as a goodantagonist of phytopathogens, but not for anthracnose inhot pepper, in the US (Bull et al., 2002) and Korea (Ahnand Kim, 2002; Chung et al., 2008; Kim et al., 1998). Bullet al. (2002) evaluated the antagonistic effects of six speciesof bacteriolytic myxobacteria, Myxococcus coralloides, M.flavescens, M. fulvus, M. stipitatus, M. virescens, and M.xanthus, against several soil-borne phytopathogens. Amongthe six, M. coralloides was the most effective for inhibitionof mycelial growth of the pathogens. Myxothiazol wasisolated and identified from M. fulvus, sprayed on diseasedplants (Kim et al., 1998), and found to be bioactive againstrice blast and tomato Phytophthora blight. Myxothiazol isan antibiotic from Myxococcus spp. (Dawid, 2000) andco

In order to predict the risk of anthracnose on hot pepper in the future, the projected climate data from SRES A1B scenario in South Korea were used with the modified anthracnose model to calculate Infection Risk (IR), which was to estimate the number of fungicide sprays. Based on daily temperature and precipitation, the anthracnose model resulted in an empirical relationship that IR

Four major diseases of chili pepper including two fungal diseases, anthracnose (Colletotrichum acutatum) and Phytophthora blight (Phytophthora capsici), and two bacterial diseases, bacterial wilt (Ralstonia solanacearum) and bacterial spot (Xanthomonas campestris pv. vesicatoria), were investigated under future climatechange condition treatments in growth chambers. Treatments with elevated CO2 and temperature were maintained at 720 ppm±20 ppm CO2 and 30oC±0.5oC, whereas ambient conditions were maintained at 420 ppm±20 ppm CO2 and 25oC±0.5oC. Pepper seedlings or fruits were infected with each pathogen, and then the disease progress was evaluated in the growth chambers. According to paired t-test analyses, bacterial wilt and spot diseases significantly increased by 24% ( p=0.008) and 25% ( p=0.016), respectively, with elevated CO2 and temperature conditions. On the other hand, neither Phytophthora blight ( p=0.906) nor anthracnose ( p= 0.125) was statistically significant. The elevated CO2 and temperature accelerated the progress of bacterial wilt by two days and bacterial spot by one day compared to the ambient treatment. Temperature regime studies of the diseases without changes in CO2 confirmed that the accelerated bacterial disease progress was mainly due to the increased temperature rather than the elevated CO2 conditions.

Field trials were conducted in Suwon, Andong, Bongwha and Taean to evaluate an anthracnose forecaster in the integrated pest management system (IPM) including anthracnose, Phytophthora blight and tobacco budworm for hot pepper in 2008-2009. Percentage of diseased fruits by pepper anthracnose and yield were compared among three treatments, no-fungicide, forecaster and conventional. The incidence and yield of the forecaster at Bongwha on two varieties were 3.1-3.5% and 30-33 kg/40 plants. These were little less than those of the conventional`s 0.3-0.8% and 35-36 kg/40 plants and much higher than those of the no-fungicide`s 23-27% and 18-24 kg/40 plants. The number of spray at the forecaster was 5 times, whereas those at the conventional was 11-19 times depending on the farmers. In addition, the results of an anthracnose forecaster at the other three field trials allowed in protecting hot pepper from anthracnose while reducing the amount of pesticides used and the total cost of the pathogen control. However, it is needed to improve for anthracnose forecaster when anthracnose pressure was high such as Taean where 60-80% of the incidence. Because the control values of the forecaster at Taean were between those of no-pesticide and conventional treatment at best. If anthracnose is severe early in the season, additional preventive control should be considered when the fruits were fully grown yet.

Department of Biomedical Sciences, Sun Moon University, Asan 330-744, Korea(Received on November 16, 2009; Accepted on December 5, 2009)A logistic model for describing combined effects of bothtemperature and wetness period on appressorium for-mation was developed using laboratory data on percentappressorium formation of Colletotrichum acutatum. Inaddition, the possible use of the logistic model for fore-casting infection risks was also evaluated as comparedwith a first-order linear model. A simplified equilibriummodel for enzymatic reactions was applied to obtain atemperature function for asymptote parameter (A) oflogistic model. For the position (B) and the rate (k)parameters, a reciprocal model was used to calculate therespective temperature functions. The nonlinear logisticmodel described successfully the response of appre-ssorium formation to the combined effects of temper-ature and wetness period. Especially the temperaturefunction for asymptote parameter A reflected theresponse of upper limit of appressorium formation totemperature, which showed the typical temperatureresponse of enzymatic reactions in the cells. By havingboth temperature and wetness period as independentvariables, the nonlinear logistic model can be used todetermine the length of wetness periods required forcertain levels of appressorium formation under differenttemperature conditions. The infection model derivedfrom the nonlinear logistic model can be used to calcu-late infection risks using hourly temperature and wet-ness period data monitored by automated weather stationsin the fields. Compared with the nonlinear infectionmodel, the linear infection model always predicted ashorter wetness period for appressorium formation,and resulted in significantly under- and over-estimationof response at low and high temperatures, respectively.Keywords : anthracnose, disease forecast, infection risk,logistic model, pepper, temperature functionColletotrichum species causes significant economic losseson fruit crops by outbreaking anthracnose in the fruitingstage (Freeman et al., 1998; Kim, 1993; Park and Kim,1992). In Korea, anthracnose caused about 13% losses oftotal pepper production during 1995 to 1999 (Shin et al.,1999). Of several species of Colletotrichum, C. capsici andC. gloeosporioides were known to be the main causalpathogens of pepper (Capsicum annuum) in Asia (Kim,1993; Manandhar et al., 1995; Park and Kim, 1992; Shin etal., 1999). However, Kang et al. (2005) recently proved thatC. acutatum was the major pathogen of pepper anthracnosein Korea by DNA homology comparison of ITS region andPCR analysis using species-specific primers.Conidia of the anthracnose pathogen produced on di-seased plant tissues are disseminated to pepper plantsmainly by wind-blown rain. The conidia deposited on plantsurface germinate and form appressoria prior to infectionunder favorable conditions. The pathogen requires wetconditions on the plant surface to infect host plants, and thelength of wetness required for plant infection depends ontemperature (Cho et al., 1987; Madden et al., 1996; Peres etal., 2005). Fungicides are commonly used to control thedisease in the field, and regular sprays at 10-day intervalsstarting from early July until 7 days prior to harvest arerecommended in Korea (Anonymous, 2008). However,unnecessary fungicides are often applied when weatherconditions are not favorable.Disease forecasts based on infection models support cropgrowers in timing the fungicide sprays only when theweather conditions are conducive for plant infections byfungal pathogens (Campbell and Madden, 1990). In manycases, infection models are polynomial equations describ-ing the response to combined effects of temperature andwetness period (Biggs and Northover, 1988; Evans et al.,1992; Lalancette et al., 1988). In order to enhance thefitness of model, the response data and/or independentvariables may be transformed prior to fitting the polynomialequations (Bulger et al., 1987; Hong and Hwang, 1998;Kim and Park, 1988; Schuh, 1991). However, the poly-nomial equations often do not reflect significance of bio-logical processes. For example, the upper limit of responseto temperature and wetness period could not be properlydescribed by the polynomial equations (Scherm and vanBruggen, 1993).

An understanding of anthracnose (Colletotrichum acutatum) infections, including the infection of flowers and latent infection early in the season, is necessary to achieve successful control by means of properly timed spraying with a curative fungicide. In the present study, latent anthracnose infection of chili was investigated under greenhouse and field conditions in 2007-2008. Flowers on greenhouse-grown seedlings were infected and 11% of the young fruits subsequently showed symptoms of anthracnose. Apparently healthy-looking green peppers obtained from unsprayed fields or an organic market also exhibited symptoms of anthracnose after 4 days of incubation under high moisture conditions at ; less than 1% of the peppers were found to be latently infected. To determine the natural timing of infection in the field, 3,200 fruits were wrapped in paper bags and then selectively unwrapped and examined for signs of infection. Field experiments were conducted at Suwon (cvs. Yokkang, Manitta, Olympic) and Asan (cv. Chunhasangsa) in 2008. The 7- to 10-day wrapping periods were July 25-31, July 31-August 7, August 7-15, August 15-24, and August 24-September 3. The 1-to 2-month wrapping periods were from July 4, July 31, and August 15 until harvest (Sept. 3). The controls consisted of 1,712 field-grown non-wrapped fruits. The rates of infection on the various cultivars were Yokkang 55%, Manitta 37%, Olympic 55%, and Chunhasangsa 20%. A distinct period in which anthracnose infection suddenly increased could not be identified; however, attempts to guess the approximate timing of field infection showed that 0-39% of the plants had latent infections, while depending on the cultivar, 8-14% of the plants examined in August and 4-13.5% of the those examined during May-July showed symptoms of infection. Delaying fungicide spraying by 24 and 48 h after artificial infection decreased the rates of infection by 10% and 25-30%, respectively. Chemical control of anthracnose based on a forecasting model should be considered starting from the transplanting stage, with spraying within a day after warning and care being taken not to latently infect apparently healthy pepper fruits.

The increased CO2 and temperature (700 μmol · mol -1 CO2 and 30oC) was compared with ambient growth conditions (400 μmol · mol -1 CO2 and 25oC) in hot pepper. Gas exchange measurements, including net photosynthesis (Pnet) and stomatal conductance (gs), were taken according to treatment in fields of peppers grown in Suwon and Asan during 2008. The increased treatment Pnet by 35-45% throughout the season and was statistically significant in t-tests (p < 0.001); however, it did not significantly affect gs. In addition, the gas exchange parameters in sun and shade leaves were measured. The difference between the sun and shade leaves was much greater than that between the elevated and ambient treatments, especially at harvest. Four commercial cultivars of hot pepper, Chunhasangsa, Ryukang, Manitta, and Olympic, were also compared by ANOVA. Chunhasangsa had the highest Pnet, which decreased by 30% from the vegetative to the harvest stage. Based on a factorial design, the effect of the increased CO2 and temperature was assessed based on the temperature, CO2, and their interaction effects. Orthogonal contrasts showed that the effects of temperature on Pnet and gs were significant, whereas CO2 and their interactions were not.

The ecophysiological changes occurring upon cold stress were studied using cold tolerant transgenic and wild-type tobacco plants. In a previous study, cold tolerance in tobacco was induced by the introduction of a gene encoding the zinc finger transcription factor, PIF1. Gas-exchange measurements including net photosynthesis and stomatal conductance were performed prior to, in the middle of, and after a cold-stress treatment of 1±2 for 96 h in each of the four seasons. In both transgenic and wild-type ℃ plants, gas-exchange parameters were severely decreased in the middle of the cold treatment, but had recovered after 2 3 h of adaptation in a greenhouse. Most t-test comparisons on gas-exchange measurements - between the two plant types did not show statistical significance. Wild-type plants had slightly more water-soaked damage on the leaves than the transgenic plants. A light-response curve did not show any differences between the two plant types. However, the curve for assimilation-internal CO2 in wild-type plants showed a much higher slope than that of the PIF1 transgenic plants. This means that the wild-type plant is more capable of regenerating Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and has greater electron transport capacity. In conclusion, cold-resistant transgenic tobacco plants demonstrated a better recovery of net photosynthesis and stomatal conductance after cold-stress treatment compared to wild-type plants, but the ecophysiological recoveries of the transgenic plants were not statistically significant.

With the goal of achieving better integrated pest management for hot pepper, a disease-forecasting system was compared to a conventional disease-control method. Experimental field plots were established at Asan, Chungnam, in 2005 to 2006, and hourly temperature and leaf wetness were measured and used as model inputs. One treatment group received applications of a protective fungicide, dithianon, every 7 days, whereas another received a curative fungicide, dimethomorph, when the model-determined infection risk (IR) exceeded a value of 3. In the unsprayed plot, fruits showed 18.9% (2005) and 14.0% (2006) anthracnose infection. Fruits sprayed with dithianon at 7-day intervals had 4.7% (2005) and 15.4% (2006) infection. The receiving model-advised sprays of dimethomorph had 9.4% (2005) and 10.9% (2006) anthracnose infection. Differences in the anthracnose levels between the conventional and model-advised treatments were not statistically significant. The efficacy of 10 (2005) and 8 (2006) applications of calendar-based sprays was same as that of three (2005 and 2006) sprays based on the disease-forecast system. In addition, we found much higher the IRs with the leaf wetness sensor from the field plots comparing without leaf wetness sensor from the weather station at Asan within 10km away. Since the wetness-periods were critical to forecast anthracnose in the model, the measurement of wetness-period in commercial fields must be refined to improve the anthracnose-forecast model.

We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient (25°C/400 ppm CO2) and twice-ambient (30°C/700 ppm CO2) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global CO2 and temperatures increase.

The interaction effects of ozone and anthracnose (Colletotrichum acutatum) disease were examined in green fruits and seedlings of pepper (Capsicum annuum). Pre-treatment with as a factor causing predisposition to the disease prior to infection was investigated in green fruits and stems using an concentration of 150 nL/L, which is easily reached in summer in Korea. treatment increased antioxidative responses in pepper foliar tissues, and defense against anthracnose was examined in fruits and stems. Anthracnose severity on stems of the , ozone-sensitive `Dabotop` cultivar was always lower than that on untreated plants, but the difference was not always significant (p

Ozone effects were studied by plant growth chamber to evaluate the impact of ozone () on the physiology of two hot pepper, Capsicum annuum L., cultivars, 'Dabotab' and 'Buchon'. Forty-day old plants with leaves were exposed to of was different from the varieties. 'Dabotab' was most sensitive to and 'Buchon' was resistant. Symptom of ozone damage on the leaves was bifacial necrosis. Decreases of net photosynthesis by were 56% and 40% on 'Dabotab' and 'Buchon', respectively. Decreases of stomatal conductance by were 66% and 63% on each variety. damage on net photosynthesis was started at the low levels of light on the two hot peppers. In addition, assimilation-internal concentration curves were not different from the two varieties. In conclusion, closed the stomata and decrease net photosynthesis on hot peppers regardless of the ozone sensitivity on leaf injury, but the difference of ecophysiological responses between the two varieties was not found clearly.

Summary • Here we conducted a series of 14C pulse-chase labeling experiments to test the hypothesis that ozone reduces allocation of recently assimilated carbon to roots of sugar maple (Acer saccharum). • Sugar maple seedlings were fumigated with 1.0 ×, 1.7 × and 3.0 × ambient ozone in open-top chambers for 3 yr under low and high light. Shoots were labeled with 14CO2 for 1 h in August of year 3, and seedlings were harvested 0, 4, 24 and 48 h after labeling. • Three years of ozone fumigation reduced total biomass of seedlings in low and high light treatments by 49% and 34%, respectively, and reduced per cent allocation of total seedling biomass to roots. Ozone similarly reduced allocation of net 14C (gross 14CO2 assimilated at time = 0 minus respiratory losses) to roots after 48 h, but not gross 14C, despite significant ozone effects on 14CO2 assimilation, leaf-level partitioning, and retention of gross carbon in shoots. • Although ozone delayed transport of 14C out of leaves initially, it had no effect on the transport process per se. Any reduction in net allocation to roots is most likely a function of changes in whole-plant source–sink relationships, with control a function of both shoot and root traits.

A soybean-sprout rot epidemic occurred in a mass production soybean sprout factory in 2000 and 2001 in Korea, which caused up to 20% production loss. Among the causal pathogenic bacteria and fungi, Pythium deliense was found to be the dominant pathogen of severe root and hypocotyls rot, particularly in recirculating water system. An average of 90% of the isolated fungi from the rotted sprout on potato dextrose agar were Pythium sp. The fungal density of Pythium in the sampled water was monitored in the recycled water system for 1 year using a selective medium (com meal agar with Pimaricin, 10 mg； Rifampicin, 10 mg； and Ampicillin, 100 mg per 1 liter). The drained water from the soybean-sprout cultivation always had a certain amount of fungus in it. The removal of Pythium from the recycling water system must be thorough, safe, and environment friendly. However, the pathogen in the water was easily found even after ozone and chlorine treatments, which were devised on the recycling system for the removal of microorganisms. 5- pore size filter was applied and was able to successfully control the disease. As the sprout industry increasingly shifts into mass production, the demand for water will increase continuously. Recycling water for sprout production is eco-friendly. However, a process must be devised to be able to first decompose organic matters before Pythium zoospores are filtered.

SUMMARY Both sensitive and tolerant clones of aspen (Populus tremuloides) were exposed to ozone using four different exposure regimes under controlled environmental conditions. Based on data on ambient ozone from 10 cities in the USA, three treatments of 4-wk exposure to the same SUM06 (an accumulation of hourly 03 concentrations greater than 0.06 ml 1-1) were constructed. The regimes allowed us to investigate: (a) the importance of long (3 wk, treatment 1) versus short (1 wk, treatment 2) duration of regimes with high peaks; (b) the effect of treatments with variable peak occurrence (treatments 1 and 2) versus uniform peak occurrence (treatment 3) during the exposure period. Nonfumigated control plants were maintained at ozone concentrations < 10 nl I-'. Bifacial black necrosis, a typical symptom of ozone injury on aspen leaves, occurred on both clones after 2 wk exposure. Up to 60 % of the leaves on the sensitive clone were injured, with an average of 6 % of total leaf area injured. In the tolerant clone only 10 % of the leaves were injured, with less than 1 % of the total leaf area symptomatic. The severity of injury was consistently greatest in treatment 2, followed by treatments 1 and 3, respectively. The interval between peak exposures was less important than the occurrence of peaks versus a stable maximum concentration. Premature leaf abscission occurred in the sensitive clone. Measures of gas exchange demonstrated reduced photosynthesis under ozone fumigation, but exposure regime was not a significant factor. Concentrations of two antioxidants, ascorbic acid and glutathione, were almost always greater in the resistant than in the sensitive clone, but the differences were not statistically significant. The levels of these antioxidants in aspen leaves did not change with ozone fumigation or leaf age.

Ozone (O3)-sensitive and tolerant clones of aspen (Populus tremuloides) were exposed to O3 at 1.0, 1.7 and 3.0 times the concentration in ambient air at Ithaca, NY, USA (×1.0, ×1.7 and ×3.0) for 3 months. Visible foliar injury occurred within a few days of the initiation of treatments and developed continuously in ×1.7 and ×3.0 treatments. Leaf senescence began earlier in trees exposed to greater-than-ambient treatments. Gas-exchange variables were measured five times over the growing season. Net photosynthesis was progressively decreased and finally reduced by 40 and 70% on tolerant and sensitive clones, respectively, but stomatal conductance was not affected by the O3 treatments. As stomatal conductance (gs) values did not differ in the two types of aspen, we conclude that this is not the defense mechanism to O3 in aspen. At the end of the season, dry weight was reduced by up to 55 and 35% in sensitive and tolerant clones, respectively. Ozone effects were significant and linear on foliar injury, biomass and growth variables such as height, diameter of stem and total leaf area. The levels of two antioxidants, ascorbic acid and glutathione, were investigated to determine if a clonal difference occurred. Concentrations of the free-radical scavengers did not differ in the clones, nor did they seem to be induced by O3. A cumulative O3 index, SUM06 (the sum of the total μl l−1 of exposure when the O3 concentration exceeded 0.06 μl l−1), was highly correlated with most foliar injury variables and gas-exchange variables except gs in higher O3 treatments. The reduction of carbon gain due to O3 is discussed with regard to foliar damage and biomass decrease.

We used cDNA microarrays to monitor the transcriptome of ozone stress-regulated genes (ORGs) in two pepper cultivars [Capsicum annuum cv. Dabotop (ozone-sensitive) and Capsicum annuum cv. Buchon (ozone-tolerant)]. Ozone stress up- or down-regulated 180 genes more than three-fold. Transcripts of 84 of these ORGs increased, transcripts of 88 others diminished, and those of eight either accumulated or diminished at different time points in the two cultivars or changed in only one of the cultivars. 67% (120) of the ORGs were regulated differently in ozone-sensitive and ozone-tolerant peppers, most being specifically up-regulated in the ozone-sensitive cultivar. Many were also represented in the plant defense transcriptome against non-host pathogen infection, and some in the transcriptomes for cold, drought, and salinity stresses.

The growth of 1-year-old aspen was simulated using TREGRO, a computer simulation model of individual tree growth, to assess potential effects of ozone (O3). TREGRO was parameterized using information from a field experiment conducted at Ithaca, NY, USA; the model was then applied using environmental information from Suwon, Korea, where O3 exposures of aspen had not been conducted. In the parameterization at Ithaca, the simulated and measured total biomass differed by about 3% and the differences between measured and simulated biomass gain of leaf, shoot, and root were 15.4, 8.3, and 4.4%, respectively. Simulating growth at Suwon required adjustment in growth rates to match measured growth due to the different weather conditions at the two cities. The assimilated carbon was evenly distributed to each tissue (foliage, branch, stem, coarse, fine roots) in Suwon, whereas it was mainly allocated to vigorous stem growth in Ithaca. The vigorous growth under Suwon conditions resulted in less total non-structural carbon and perhaps trees more vulnerable to O3 stress. Although the ambient O3 in Suwon (1.2 ppm.h of sum of the hourly concentrations greater than 0.06 ppm [SUM06]) was lower than that in Ithaca (2.1 ppm.h of SUM06), a reduction of 8% of total assimilated carbon was found compared to simulation without O3. Severe effects on root growth at elevated O3 (1.7 times ambient) were predicted; however, the effects on leaf growth would not be as severe.

Since 1931, sporadic reports have appeared noting an apparent association between hyperthyroidism and idiopathic thrombocytopenic purpura. Recent various studies suggested that these two diseases may share a similar immunologic background, but the the exact mechanism is still a matter of speculation. This 22-year old female patient visisted this hospital because of general weakness and purpura of legs for 2 months. The laboratory findings were compatible with Graves' disease associated with idiopathic thrombocytopenic purpura. The palatclet count was 16000/, hemoglobulin was 10.9g/dl and MCV was 60.1tL. T3 was 490.53ng/dL, T4 was 24ug/dL and free T4 was 5.66ng/dL. Antiplatelet antibody and anti-microsomal antibody were positive. The bone marrow findings were compatible with tron deficiency anemia and idiopathic thrombocytopenic purpura. The thyroid biopsy showed adenomatous goiter. She was administered with propyl thiouracil, Beta-blocker, iron and prednisolon. On the 10th hospital day, platelet count was 184000/, hemoglobulin was 12.0gm/dL and MCV was 67.5fL. On the 20th hospital day, T4 was 10.35ug/dL and free T4 was 2.30ng/dL. Therefore she was discharged and followed up.

To evaluate the features of pyuria related to the bacteriuria, 140 subjects were studied from Jan. 1987 to Dec. 1987. The pyuria was frequently developed from the age 30 to 60 years old, and male to female ratio was 1:1.41. The most common disease was urethrocystitis that was shown 42.8%. Common precipitating factors were urethral catheterization(25%) and urinary tract obstruction(11.4 %). Through the observation, symptomatic pyuric patients were 66 subjects(47.1%), and the subjects with significant urine culture were 121 subjects(86.4%). In the urine culture, the most common bacteria was E. coli(41.4%), and the next was Pseudomonas(19.3%). A large percentage of E. coli and Pseudomonas was susceptible of amikin. The pyuria due to S. epidermidis and Accinatobacter was well treated. High therapeutic rate was observed in the acute pyelonephritis(71%) and urethrocystitis(67%). In the persistent urinary tract infection, there were relapsing(22 cases) and recurrent urinary tract infection(16 cases).