• 식물병연구
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• 제25권3호
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• pp.108-113
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• 2019

북한의 작물 생산성은 남한에 비하여 월등히 낮다. 이러한 이유 중 하나는 취약한 병 관리에 있다. 북한은 농경지의 약 30%가 논으로 이루어져 있다. 벼 도열병과 벼 흰잎마름병은 북한 벼 재배 시 각각 가장 중요한 곰팡이 병 및 세균 병이다. 본 연구에서는 벼 도열병균과 벼 흰잎마름병균에 대한 7개 북한 벼 품종의 병 저항성 반응을 시험하였다. 남한에서 분리한 18개 벼 도열병균에 대한 7개 벼 품종의 반응은 다소 다르게 나타났다. 7개 벼 품종 중 길주1호는 KI 혹은 KJ 레이스에 관계없이 남한에서 분리한 벼 도열병균 18개 균주 모두에 매우 저항성을 보였다. 평도5호는 남한에서 분리한 벼 도열병균 15개 균주에 대하여 감수성 반응을 보였다. 반면, 벼 흰잎마름병균에 대한 북한 벼 품종의 병 저항성 반응은 벼 도열병균에 대한 반응과 차이를 보였다. 길주1호는 K1 레이스인 KXO42와 K2 레이스인 KXO90에 대하여 높은 감수성을 보였고, 평도5호는 K1 레이스인 KXO85와 K3 레이스인 KXO19에 완전한 저항성을 보였다. 평양21호는 K1 레이스 모두에 완전한 저항성을 보였고, 원산69호는 KXO85를 제외한 모든 벼 흰잎마름병균에 감수성을 보였다. 이 연구는 향후 남북 농업 협력을 통하여 북한 벼 품종을 남한에 도입 시 두 병원균에 대한 북한 벼 품종의 저항성 반응 검정 및 벼 품종 육성에 중요한 기본 자료가 될 것이다.

• 식물병연구
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• 제15권3호
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• pp.230-235
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• 2009

배 저장 중 신고에서 발생되는 과피얼룩 및 부패증상의 발생억제를 위해 2년간 시험한 결과 수확 후 약제 또는 생물제제 살포로 발병을 억제할 수 있었으며, 살포시기가 늦어질수록 발병가능성은 높은 것으로 나타났다. 한편, 처리시기와 관련하여 과실 수확 후 6주 또는 그 이후 처리는 상처부위의 부패 발생 억제효과가 낮았다. 그러나 TBZ를 수확 3~6주에 처리시 저장중 과피얼룩 및 부패과 발생은 현저히 억제되었다. 또한, TBZ, Fludioxonil과 Pyrimethanil 처리에 의한 과피얼룩 및 부패과 발생은 상처접종 처리에서 최대 14일까지 발병이 억제되었다. 그리고 수확시 TBZ 및 3주 후 Fludioxonil 처리는 수확시 TBZ 단용처리보다 발병억제력이 높았다. 한편, 2종의 생물제제(EXTN-1, Bio-Save 110)는 C. tenuissimum 접종처리에서 저장 14일까지 발병을 억제하여 저장 유통중 발생하는 상처부위 발병 억제가 가능 할 것으로 판단되었다. 결론적으로 저장 중 과피얼룩 및 부패방제를 위해 서로 다른 약제조합을 수확 후 저장 전에 처리할 때 가장 높은 방제효과를 얻을 수 있었다.

• The Plant Pathology Journal
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• 제40권2호
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• pp.160-170
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• 2024

Erwinia amylovora is a plant pathogen that causes fire blight on apples and pears. Bacteriophages, which are viruses that selectively infect specific species of bacteria and are harmless to animal cells, have been considered as biological control agents for the prevention of bacterial pathogens. In this study, we aimed to use bacteriophages that infect E. amylovora as biocontrol agents against fire blight. We isolated bacteriophages Fifi044 and Fifi318 infecting E. amylovora, and characterized their morphology, plaque form, and genetic diversity to use as cocktails for disease control. The stabilities of the two phages were investigated at various temperatures and pH values and under sunlight, and long-term storage experiment was conducted for a year. To evaluate whether the two phages were suitable for use in cocktail form, growth curves of E. amylovora were prepared after treating the bacterial cells with single phages and a phage cocktail. In addition, a disease control test was conducted using immature apples and in vitro cultured apple plantlets to determine the biocontrol effects of the phage cocktail. The two phages were morphologically and genetically different, and highly stable up to 50℃ and pH value from 4 to 10. The phages showed synergistic effect when used as a cocktail in the inhibition of host bacterial growth and the disease control. This study demonstrated that the potential of the phage cocktail as a biocontrol agent for commercial use.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.867-874
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• 2011

This paper describes the results of a survey aimed at characterizing smallholder pig production systems in northern Lao PDR. A total of 341 households from five Northern provinces were interviewed in the survey. Village meetings and individual interviews, using a semi-structured questionnaire, were used to collect information. Three main pig rearing systems, free-scavenging, semi-scavenging and confinement (enclosures and pens), were found in the survey areas. These systems were practiced differently by smallholders depending on the level of intensity of crop production, ethnicity and purpose of keeping pigs. The confinement system was mainly practiced by Lao-Tai and Tibeto-Burman groups, who mainly bought piglets and fattened these pigs for sale. In contrast, the Mon-Khmer and Hmong-Mien reared pigs in free-scavenging and semi-scavenging systems, and usually keep sows for piglet production. The main factors that affected the changes in rearing systems were found to be level of intensity of crop production, local regulations and outbreaks of disease. The main constraints found in smallholder systems were outbreaks of disease, high mortality of piglets and the slow growth rate of fattening pigs.

• 식물병연구
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• 제30권3호
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• pp.283-287
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• 2024

임실군농업기술센터에서 전시용으로 재배 중인 국화 잎에 갈색에서 검은색의 반점이 형성되고, 시간이 지날수록 병반이 확대되며 심하면 식물체가 고사하는 증상이 나타났다. 국화의 병든 잎 부위에서 병원균을 분리하여 ITS, TUB2, ACT 유전자 염기 서열 분석을 통해 동정한 결과 Epicoccum sorghinum으로 확인되었다. 분리된 균의 균학적 특성을 확인해 본 결과, PDA 배지에서 배양한 균을 UV 광에 12시간 동안 노출 후 암실에 두었을 때 병자각이 형성되었으며, 격벽이 없는 타원형의 무색 투명한 분생포자(3.2-6.0×1.7-3.0 ㎛)가 형성되는 것을 확인할 수 있었다. PDA 배지에서 배양한 균주의 agar plug를 국화 잎에 접종하여 병원성을 검정한 결과, 접종한 국화 잎에서 담갈색에서 검은색의 불규칙한 모양의 병반이 형성되었다. 따라서 E. sorghinum에 의한 국화 점무늬병을 국내 처음으로 보고하고자 한다.

• The Plant Pathology Journal
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• 제28권4호
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• pp.454-454
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• 2012

• Mycobiology
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• 제43권3호
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• pp.343-346
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• 2015

In 2006~2010, leaf spot symptoms, that is, small, yellow spots that turned into dark brown-to-black lesions surrounded by a yellow halo, were observed on Cymbidium spp. in Gongju, Taean, and Gapyeong in Korea. A Fusarium species was continuously isolated from symptomatic leaves; in pathogenicity testing, isolates caused leaf spot symptoms consisting of sunken, dark brown lesions similar to the original ones. The causal pathogen was identified as Fusarium subglutinans based on morphological and translation elongation factor 1-alpha sequence analyses. This is the first report of F. subglutinans as the cause of leaf spot disease in Cymbidium spp. in Korea.

• 한국균학회지
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• 제52권1호
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• pp.19-24
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• 2024

Rice sheath rot causes yield losses of up to 85% in rice-growing areas worldwide. In September 2023, the disease was detected in rice fields at the National Institute of Agricultural Sciences in Wanju, Korea. Two isolates (FD00214 and FD00215) were collected from symptomatic rice sheaths and identified as Sarocladium strictum based on their morphological characteristics and molecular sequencing of two genomic regions: the internal transcribed spacer and actin. Pathogenicity tests confirmed that S. strictum were the cause of the disease. To our knowledge, this is the first report of rice sheath rot caused by S. strictum in South Korea.

• Mycobiology
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• 제46권3호
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• pp.283-286
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• 2018

Fusarium graminearum causes the devastating plant disease Fusarium head blight and produces mycotoxins on small cultivated grains. To investigate the timeframe of F. graminearum infection during rice cultivation, a spore suspension of F. graminearum was applied to the rice cultivars Dongjin 1 and Nampyeongbyeo before and after the heading stage. The disease incidence rate was the highest (50%) directly after heading, when the greatest number of flowers were present, while only 10% of the rice infected 30 days after heading showed symptoms. To understand the mechanism of infection, an F. graminearum strain expressing green fluorescent protein (GFP) was inoculated, and the resulting infections were visually examined. Spores were found in all areas between the glume and inner seed, with the largest amount of GFP detected in the aleurone layer. When the inner part of the rice seed was infected, the pathogen was mainly observed in the embryo. These results suggest that F. graminearum migrates from the anthers to the ovaries and into the seeds during the flowering stage of rice. This study will contribute to uncovering the infection process of this pathogen in rice.

• 한국약용작물학회지
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• 제23권3호
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• pp.198-206
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• 2015

This study was conducted to investigate the effects of sowing density, number of seeds sown per hole, and thinning treatment on growth characteristics and disease occurrence in Panax ginseng under direct sowing cultivation in a blue plastic greenhouse. Seedling were grown from 2 or 3 seeds sown, and the healthiest was only retained, while the rest were thinned out at the foliation stage. $NO_3$-N, $P_2O_5$, and organic matter content differed significantly between growth conditions in the plastic greenhouse and in conventional shade in the soil. Disease also tended to be higher in the conventional shade than in the plastic greenhouse. Plant height and stem length showed an increasing trend with increasing sowing density and number of seeds sown per hole. However, these measures noticeably decreased when thinning treatment was conducted. Growth of the subterranean part of ginseng was not markedly influenced by sowing density, the number of seeds sown per hole, or thinning treatment. Root weight, which is an important factor in yield, was significantly affected by the number of seeds sown and thinning treatment. Interestingly, root weight tended to be higher in the thinning treatment plot than the untreated control plot. Damping-off and root rot increased noticeably as the number of seeds sown increased. Disease also tended to be substantially higher in the thinning treatment plot than the untreated control. However, physiological disorder of the plants did not vary with sowing density, the number of seeds sown, or thinning treatment.