• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.98.2-99
• /
• 2003

Bacterial canker of sweet cherry (Prunus cerasus L.) was observed in farmers' orchard in Goesan, Chungbuk in 2003. Typical canker symptom occurred on the branches or twigs of sweet cherry in early spring and bacterial exudates oozed out of the cracked barks of diseased trees. Watersoaked brown symptom appeared on the leaves and severe infection caused thorough defoliation on the branches or twigs of sweet cherry. When cut the severely infected branches or twigs, irregular and rusty-colored symptoms in sapwood and heartwood were clearly found, indicating that they could serve as specific symptoms of bacterial canker of sweet cherry. The gram negative, aerobic bacterium isolated from the lesion produced fluorescent pigments on King's B agar medium but did not grow at 37$^{\circ}C$ The bacterium formed Levan-type colonies, and showed negative reactions in oxidase reaction, arginine dihydrolysis test, and pectolytic activity Based on the biochemical and pathological characteristics, the causal organism was identified as Pseudomonas syringae pv. morsprunorum. This is the first report on bacterial canker of sweet cherry in Korea.

• 한국유기농업학회지
• /
• 제24권3호
• /
• pp.435-451
• /
• 2016

본 연구는 유기재배와 관행재배지의 토양화학성 및 인삼의 생육특성을 비교 분석하기 위하여 수행하였다. 유기재배 인삼과 관행재배 인삼 시료 채취는 전국 14개 지역 52개 포장에서 4, 5, 6년근을 대상으로 2013년부터 2015년까지 3년에 걸쳐 10월부터 11월까지 2개월 동안 이루어졌다. 인삼 유기재배에서는 수량을 높이기 위해 관행재배지와 비슷하게 양분의 함량이 높아지고 있어 토양화학성기준에 맞는 적합한 관리가 요구된다. 유기재배 인삼은 관행재배 인삼보다 생육기간이 60일 이상 짧은 특징을 보였으며 1 ha당 평균 수량도 관행 수량의 60% 수준이었다. 근중은 유기재배 인삼이 관행재배 인삼의 54% 정도였다. 동직경 및 체형계수도 유기재배 인삼이 관행재배보다 더 작아 유기재배 인삼이 가늘고 긴 특징을 보였다. 근장은 답전윤환지의 비율이 낮은 관행재배 인삼 5년근에서 길었다. 지근의 수는 직파재배의 비율이 높은 유기재배 인삼 5, 6년근에서 적었다. 건물중은 관행재배보다 조기낙엽이 발생된 유기재배 인삼의 5, 6년근에서 뚜렷하게 낮았다. 동할과 뿌리썩음병은 관행재배에서 많은 경향이었는데 동할은 4, 6년근에서 뚜렷하게 많았으며 뿌리썩음병은 5, 6년근에서 많이 발생되었다. 토양수분의 영향을 많이 받는 적변과 선충의 피해는 유기재배 4년근에서 많았다. 즉 유기재배 인삼은 관행재배보다 조기낙엽 현상이 뚜렷하여 수량 및 근중이 낮은 반면 생리장해는 적었다. 유기재배 인삼의 수량을 높이기 위해서는 조기낙엽의 문제를 극복할 수 있는 재배 기술적인 연구가 필요하며 생리장해를 줄일 수 있는 토양 수분관리가 필요하다.

• 한국환경농학회지
• /
• 제33권1호
• /
• pp.57-62
• /
• 2014

BACKGROUND: Defoliation in grapevine cultivation is practically used to improve light environment within the canopy and thereby fruit quality. Effects of defoliation in five-year-old 'Pione' grapevine during cultivation with heating were investigated to find out optimum ratio of leaf area to fruit cluster weight (L/F). METHODS AND RESULTS: The grapevines were defoliated with berry-thinning 20 days after full bloom to provide various levels of L/F. At harvest, total leaf area values of fruit bearing branches were between 0.23 and $0.60m^2$. With increasing L/F, soluble solids and anthocyanin contents curvilinearly increased ($R^2=0.76^{**}$). At L/F over $0.6m^2/kg$, soluble solids content (SSC) leveled off. With increasing L/F, titratable acidity (TA) linearly decreased ($R^2=0.87^{**}$), but the ratio of SSC to TA linearly increased ($R^2=0.86^{**}$). Anthocyanin content was significantly correlated with SSC and the ratio of SSC to TA ($R^2=0.80^{**}$ and $0.82^{**}$, respectively). When total leaf area per fruit bearing branch was maintained $0.40m^2$, soluble solids and anthocyanin contents linearly decreased ($R^2=0.79^{**}$ and $0.85^{**}$, respectively), but TA linearly increased with increasing fruit cluster weight ($R^2=0.70^{**}$). Fruit was low in quality when the L/F was below $0.6m^2/kg$. CONCLUSION: L/F is recommended to be maintained at least $0.6m^2/kg$ in 'Pione' grapevine during cultivation with heating to produce higher-quality fruits.

• 한국응용곤충학회지
• /
• 제37권2호
• /
• pp.193-198
• /
• 1998

유자(Citrus junos T.) 과원의 주요 해충의 귤응애(Panonychus ？갸 M.)의 발생소장, 온도별 발육기간, 산란수, 부화율 및 유자유목의 생육에 미치는 영향을 구명하고자 1996년부터 1997년까지 2년간 조사한 결과, 귤응애는 5월부터 11 월까지는 발생하였는데 년 2회의 발생최성기를 이루었다. 1차 발생최성기는 7~8월이고, 2차발생최성기는 10월이었다. 2차 발생최성기에는 잎당밀도 9.5마리로 연중 최대발생량을 보였다. 유자 잎에서 귤응애의 각 태별 구성비는 난, 약충, 성충이 각각 85, 9, 6%로 난의 비율이 월등히 높았다. 15, 20, 25, $\pm$1$^{\circ}C$(RH 60 $30\pm$10%, 14L-10D)의 항온조건에서 난부터 성충까지 발육기간은 각각 41.1, 15.5, 11.0, 9.4일이고 성충수명은 23.3, 8.3, 6.3, 6.1일로 온도가 높을수록 발육기간과 성충수명은 짧아지는 경향이고 부화율은 $30^{\circ}C$에서 94.7%로 가장 높았다. 일평균 산ㄹ나수는 $25^{\circ}C$에서 4.5개로 가장 많았다. 또, 귤응애 방제밀도에 따른 유자유목의 생육상황은 방제밀도가 낮을수록 간주 및 수관용적 증가량이 많았고 엽록소함량도 많았다. 월동후 낙엽율은 1, 3, 6마리/잎, 무방제에서 각각 13.5, 20.6, 53.1, 72.6%로 잎당 성충밀도 3마리 이하에 방제하는 것이 낙엽율이 낮았다.

• 생물환경조절학회지
• /
• 제31권4호
• /
• pp.325-331
• /
• 2022

토마토의 생육과 수확량을 예측하기 위한 중요한 요소 중의 하나는 엽면적이다. 이러한 엽면적을 정확하게 예측하는 것은 토마토 식물 생장 평가 모델의 시작이라고 할 수 있다. 이를 위해 본 연구는 토마토 잎의 측정을 통해 엽면적(LA)을 추정하는 효과적인 모델을 확인하기 위해 수행하였다. 토마토 식물 잎 조사를 위해 2주 간격으로 5개체의 토마토 식물체의 전개된 모든 잎에 대해 엽면적(LA), 엽장(L), 엽폭(W), 엽신장(La)를 측정하였다. LA와 토마토 잎 독립변수의 상관관계는 La × W, L × W, La + W, L + W의 식이 강한 양의 관계를 나타냈다. LA 추정은 LA = a + b(La² + W²)을 사용하는 선형 모델이 가장 정확한 추정치를 나타내었다(R² = 0.867, RMSE = 88.76). 9월부터 12월까지 토마토 잎의 위치에 따른 상, 중, 하 엽의 모델을 살펴본 결과, 상, 중, 하로 잎 위치에 따른 모델별 결정계수(R²) 값은 각각 0.878, 0.726, 0.794였다. 상위엽을 바탕으로 추정된 모델의 정확도가 가장 높았는데, 이는 10월 이후 토마토 재배 농가에서 중위엽과 하위엽에 실시한 반적엽의 영향으로 판단된다.

• 원예과학기술지
• /
• 제33권3호
• /
• pp.429-434
• /
• 2015

Apple blotch-like symptoms (ABLS) were observed on 'Fuji' apple leaves in Cheongsong, Gunwi and Yeongcheon apple orchards located in Gyeongbuk Province during 2010-2014. Characteristics of ABLS were yellowing, brown spots on leaves, and defoliation, similar to apple blotch diseased (ABD) leaves, which are infected with Marssonina coronaria. It is difficult to differentiate by eye between ABLS and ABD, which has led to misdiagnosis and overuse of fungicides. The present study was conducted to investigate the cause of ABLS using stereomicroscopy, culture isolation, cross-sectional analysis of leaves, and PCR. No acervuli were found on the surface of ABLS leaves and no growth was observed on potato dextrose agar (PDA) plates in culture. Furthermore, cross-sectional analysis revealed similar results, and mycelia were absent in ABLS leaves. By contrast, all these characteristics were present in ABD leaves. Furthermore, no fungi or viruses were detected in ABLS leaves by PCR, suggesting that the disease is not caused by these agents. These findings suggest that ABLS might be a physiological disorder in plants that is distinct from ABD.

• The Plant Pathology Journal
• /
• 제34권1호
• /
• pp.1-10
• /
• 2018

A previously unreported bacterial disease on chili pepper (Capsicum annuum L.) seedlings affecting as many as 4% of seedlings was observed in greenhouses in Chihuahua, Mexico (Delicias and Meoqui counties). Initial lesions appeared as irregular small spots on leaves and brown necrosis at margins tips were observed. Later, the spots became necrotic with a chlorotic halo. Advanced disease was associated with defoliation. A Gram negative, rod-shaped bacterium was isolated from diseased chili pepper seedlings. Three inoculation methods revealed that isolated strains produce foliage symptoms, similar to those observed in naturally infected seedlings. Pathogenic strains that caused symptoms in inoculated seedlings were re-isolated and identified to fulfill koch's postulate. Polyphasic approaches for identification including biochemical assays (API 20E and 50CH), carbon source utilization profiling (Biolog) and 16S rDNA, hsp60 and rpoB sequence analysis were done. Enterobacter cloacae was identified as the causal agent of this outbreak on chili pepper seedlings.

• 식물병연구
• /
• 제9권3호
• /
• pp.166-169
• /
• 2003

고추재배에서 갈색점무늬병에 의한 반점 황화 조기낙엽 등의 피해로 수량감소를 일으키고 있어, 이 병해에 대한 저항성 육종을 위해서 병원균의 인위접종에 의한 발병조건을 확립하고자 한다. 본 실험 결과, 발병온도는 접종 후 야간 15~$20^{\circ}C$/주간 20~$25^{\circ}C$에서 습실을 경과하는 것이 발병이 가장 양호하였다. 접종묘령은 접종 후 병반 형성수가 많으면서 낙엽이 적게되는 30~40일 유묘가 발병이 가장 좋았다. 고추 유묘에 포자현탁액으로 접종할 경우 3.4 ${\times}$ $10^5$ conidia/ml 농도가 적당하며 접종 후 병반수로 저항성 정도를 조사할 때 20일까지 적당하였다.

• 한국대기환경학회지
• /
• 제8권1호
• /
• pp.7-12
• /
• 1992

This study was conducted to determine the effectiveness of silver thiosulfate(STS) in reducing $O_3$ injury to tomato plants(Lycopersicon esculentm Mill. 'Pink Glory'). Two days prior to $O_3$ fumigation, plants were given a foliar spray of STS solution at concentrations of 0, 0.2, 0.4, 0.6 mM contained with 0.05% Tween-20. STS concentrations below 0.6 mM were significantly effective in providing protection aginst $O_3$ exposure(16 h at 0.3 ppm). STS reduced leaf injury rate, defoliation of cotyledons, ethylene production and degree of epinasty induced by $O_3$ injury. STS slightly increased ethylene production in non-$O_3$-fumigated plants, but changes of chlorophyll content and transpiration rate on a whole plant basis were not observed. In $O_3$-fumigated plants, STS treatment reduced chlorophyll destruction but did not affect transpiration rate. STS treatment seemed not to affect peroxidase(POD) and superoxide dismutase (SOD) activity in non-fumigated plants but reduced increasing activity of POD by $O_3$ fumigation. However, such an effect as above was not found in SOD activity. Even though enzymatic protection effects were not confirmed, the fact that reduction of acute injury rate was attained for 16 h fumigation indicates that the phytoprotective effects of STS are not necessarily related to blocking the action of strees-induced-ethylene as an anti-ethylene agent.

• Journal of Plant Biotechnology
• /
• 제30권2호
• /
• pp.167-172
• /
• 2003

Immature zygotic embryos of Eleutherococcus senticosus seeds matured rapidly within one month when the seeds comprising zygotic embryos were pieced to small size and cultured on 1/2 MS medium. Frequency of somatic embryos formation was declined rapidly when the zygotic embryos germinated and grew to plantlets. Embryogenic cells were induced by consecutive subculture of somatic embryos on MS medium with 1.0mg/L2,4-D. After heart-shaped somatic embryos were induced by suspension culture, these embryos were plated onto petri dish to support maturation of embryos. Germination of embryos occurred on medium with 5mg/L GA$_3$and transferred to culture bowl to stimulate the further growth. Frequency of soil survival of plantlets was influenced by soil mixture (perlite and peatmoss). The suitable combination of perlite and peatmoss was 1:5, and the soil survival rate was 78% after 4 months. The soil transferred plantlets were over-wintered in field condition after defoliation. New year sprouting of plants was achieved successfully and they grew to adult plants. These results indicate that the systematic procecure of plant production in E. senticosus for micro propagation.