• The Plant Pathology Journal
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• 제31권4호
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• pp.363-370
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• 2015

Using the Chinese cabbage (Brassica campestris) cultivar 'Chun-goang' as a host and turnip mosaic virus (TuMV) as a pathogen, we studied the effects of ambient temperature ($13^{\circ}C$, $18^{\circ}C$, $23^{\circ}C$, $28^{\circ}C$ and $33^{\circ}C$) on disease intensity and the speed of systemic infection. The optimal temperature for symptom expression of TuMV was $18-28^{\circ}C$. However, symptoms of viral infection were initiated at $23-28^{\circ}C$ and 6 days post infection (dpi). Plants maintained at $33^{\circ}C$ were systemically infected as early as 6 dpi and remained symptomless until 12 or 22 dpi, depending on growth stage at the time of inoculation. It took 45 days for infection of plants grown at $13^{\circ}C$. Quantitative realtime polymerase chain reaction (q-PCR) results showed that the accumulation of virus coat protein was greater in plants grown at $23-28^{\circ}C$. The speed of systemic infection increased linearly with rising ambient temperature, up to $23^{\circ}C$. The zero-infection temperature was $10.1^{\circ}C$. To study the effects of abruptly elevated temperatures on systemic infection, plants inoculated with TuMV were maintained at $10^{\circ}C$ for 20 d; transferred to a growth chamber at temperatures of $13^{\circ}C$, $18^{\circ}C$, $23^{\circ}C$, $28^{\circ}C$, or $33^{\circ}C$ for 1, 2, or 3 d; and then moved back to $10^{\circ}C$. The numbers of plants infected increased as duration of exposure to higher temperatures and dpi increased.

• 한국유기농업학회지
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• 제7권2호
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• pp.107-114
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• 1999

몇가지 土壤微生物劑의 處理가 배추의 收量과 土壤 및 植物體의 化學成分, 그리고 微生物相에 미치는 影響을 調査하였다. 모든 微生物劑 處理區에서 無處理에 비하여 收量이 增加하였고, 糖度 또한 增加하여 微生物劑의 處理가 배추의 收量뿐만 아니라 品質의 向上에도 매우 效果的이라고 思料되었다. 植物體의 化學成分을 調査한 結果, MPK+Compost 處理區에서 Fe와 Zn 含量이 매우 높았으나 有意性은 없었고, 다른 成分들은 處理區間에서 差異가 없었다. 土壤의 化學成分에서는 Tomi 處理區에서 K와 Mg의 含量이 높았으나, 다른 處理區에서는 差異가 없었다. 土壤의 微生物相을 調査한 結果, 總細菌數에서는 Tomi 處理區가 가장 높았고 Husk+Palma 및 MPK+Husk+Palma 處理區에서도 높게 나타났다. Bacillus는 MPK+Husk+Palma 處理區가 가장 높았고 Husk+Palma와 Tomi 處理區에서도 몹시 增加되었다. Actinomycetes와 fungi에서도 Tomi 處理區가 매우 增加하였으나, 다른 處理區間에는 差異가 없었고, psedomonas에서도 各 處理間에 差異가 없었다.

• Journal of Applied Biological Chemistry
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• 제44권3호
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• pp.119-124
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• 2001

NTR1 gene of Brassica campestris L. ssp. perkinensis encodes a floral nectary-specific methyltransferase. In this study, the NTR1 cDNA was expressed in E. coli to examine the enzymatic characteristics of the protein product. The GST-NTR1 fusion protein was purified to near homogeneity, showing that the size of NTR1 was 44 kDa. The protein reacted specifically with jasmonic acid (JA), consuming methyl group from S-adenosyl-L-methionine (SAM). GC-MS analysis revealed that the compound produced was authentic methyl jasmonate (MeJA), suggesting that NTR1 is an S-adenosyl-L-methionine: jasmonic acid carboxyl methyltransferase. Km values of NTR1 for JA and SAM were 38.0 and $6.4{\mu}M$, respectively. Optimal activity of the NTR1 was observed at $20^{\circ}C$, pH 7.5, in the presence of 100-150 mM KCl. Thus, kinetic properties, thermal characteristics, optimal pH, and ion-dependency of the NTR1 activity were almost identical to those of Arabidopsis JA methyltransferase JMT, indicating that these two proteins are orthologues of each other.

• 한국잡초학회지
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• 제4권1호
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• pp.96-106
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• 1984

Changes in weed floras and development of plant resistance to herbicides seemed to be closely related with increased and repeated use of herbicides. Herbicide use increased from 5% of the total consumption of pesticide in 1950 to 45% in 1976 in world basis. About 200 herbicides have been introduced to agriculture so as to control about 206 weed species which have been recorded important to human beings. In Korea, there was about 351 times in increased use of herbicides from 1966 to 1982. Interspecific selection by herbicide is mainly responsible for changes in weed floras and resulted in varying tolerance or susceptibility to herbicides, together with the changes of agricultural practices. The present trend toward continuous cereal cultivation throughout world will lead to type of changes in weed floras favorable to therophyte which can survive under unfavorable conditions as seeds rather than the types of geophyte which can survive unfavorable seasons as buds placed below soil surface. However, geophyte such as Sagitaria pygmaea, and Scirpus jurtcoides, and Cyperus rotundus and Cynodon dactylon in temperate warm climate become severe paddy weeds, presumably because of the removal of annual weeds by herbicides. Since differential tolerance to 2,4-D was firstly reported in Agrostis stolofera, about 30 species of weeds in 18 genera are presently known to have developed resistance to triazine herbicides. Resistance of weed biotypes to triazine herbicide is not mainly due to limited absorption and translocation or to the difference in metabolism, but is the result of biochemical changes at the site of metabolic activity, such as a loss of herbicide affinity for triazine binding site in the photosystem II complex of the chloroplast membrane. Genetical study showed that plastid resistance to triazine was wholly inherited through cytoplasmic DNA in the case of Brassica campestris. Plant tissue culture method can be utilized as an alternate mean of herbicide screening and development of resistance variants to herbicides as suggested by Chaleff and Parsons. In this purpose, one should be certain that the primary target process is operational in cell culture. Further, there are a variety of obstacles in doing this type of research, particularly development of resistance source and it's regeneration because cultured cells and whole plants represent different developmental state.

• The Plant Pathology Journal
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• 제30권2호
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• pp.125-135
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• 2014

A population model of bacterial spot caused by Xanthomonas campestris pv. vesicatoria on hot pepper was developed to predict the primary disease infection date. The model estimated the pathogen population on the surface and within the leaf of the host based on the wetness period and temperature. For successful infection, at least 5,000 cells/ml of the bacterial population were required. Also, wind and rain were necessary according to regression analyses of the monitored data. Bacterial spot on the model is initiated when the pathogen population exceeds $10^{15}cells/g$ within the leaf. The developed model was validated using 94 assessed samples from 2000 to 2007 obtained from monitored fields. Based on the validation study, the predicted initial infection dates varied based on the year rather than the location. Differences in initial infection dates between the model predictions and the monitored data in the field were minimal. For example, predicted infection dates for 7 locations were within the same month as the actual infection dates, 11 locations were within 1 month of the actual infection, and only 3 locations were more than 2 months apart from the actual infection. The predicted infection dates were mapped from 2009 to 2012; 2011 was the most severe year. Although the model was not sensitive enough to predict disease severity of less than 0.1% in the field, our model predicted bacterial spot severity of 1% or more. Therefore, this model can be applied in the field to determine when bacterial spot control is required.

• Applied Biological Chemistry
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• 제35권1호
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• pp.30-35
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• 1992

Polyvinyl alcohol(PVA)을 탄소원으로 이용할 수 있는 세균 J2W 균주와 J2Y균주를 토양으로 부터 분리하였다. 분리된 이들 균주는 각각 별도의 순수배양으로는 PVA를 이용할 수 없었으나 이들 균주를 혼합배양 하였을 경우는 PVA를 분해 이용할 수 있었으며, 또한 PVA의 중합도(중합도 500, 1500, 2000)에 관계없이 이용할 수 있었다. 이들 두 균주는 다른 PVA 이용 공생균주 Pseudomonas PW와 Pseudomonas G5Y와 재구성하여 혼합배양 하였을 때 J2Y균주와 Pseudomonas PW, J2W 균주와 Pseudomonas G5Y 균주와의 혼합배양에서는 PVA를 이용할 수 있었다. 이들 두 균주는 동정 결과 J2W균주는 Pseudomons pseudomallei 근연균으로, J2Y는 Xanthomonas campestris 근연균으로 동정되었다.

• 원예과학기술지
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• 제19권1호
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• pp.7-11
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• 2001

1998-1999년도에 걸쳐 총 238점의 고추 유전자원에 대하여 흰가루병에 대한 저항성을 검정한 결과, Capsicum baccatum에 속하는 KC604, 605, 606, 608, C. chinense에 속하는 KC616, C. pubescens에 속하는 KC638, 640, 641, 642, 643, 644가 발병하지 않을 정도로 고도의 저항성을 나타내었으며 C. annuum에 속하는 KC47-1(PI244670), KC319-1, KC545, KC320는 경미하게 발병하여 다소 저항성으로 나타났다. KC47-1, KC319-1, KC320은 Stemphylium spp.에 의한 고추 잎점무늬병에 저항성이며, 그 중 KC 47-1은 더뎅이병(Xanthomonas campestris pv. vesicatoria)에도 저항성이어서 이들 병에 복합저항성 육성도 가능할 것으로 기대된다.

• 한국식물병리학회지
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• 제2권3호
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• pp.150-157
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• 1986

벼흰빛잎마름병균의 균주를 효과적으로 보관하기 위하여 동결건조, 동결, 액체파라핀, 살균수, 계대배양등의 방법을 사용하여 생존율과 병원성유지 정도를 4개월에 걸쳐 조사하였다. 실험결과 $10\%$ sucrose와 $1\%$ gelatin을 함유한 현탁액에서 가장 높은 생존율을 나타냈으며 병원성은 $2\%$ dextrin, $0.5\%$ ascorbic acid, $0.5\%$ ammonium chloride, $0.5\%$ tguiyrea, $0.85\%$ NaCl 등을 함유한 현탁액에서 가장 잘 유지되었다. 계대배양한 균주는 병원성이 약화되었다. 거친집락형은 동결건조 또는 동결과정에서 모두 나타났으며 이는 정상집락에 반해 주름진 집락모습과 사상형이었다. 거친집락형은 병원성이 매우 약하였으며, 탄소원 요구도가 다양하였으므로 동결건조 과정에서 대사작용의 저해가 일어난 것으로 추측되었다.

• The Plant Pathology Journal
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• 제24권4호
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• pp.478-481
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• 2008

The cDNA clone of Brassica rapa WRKY7 (BrWRKY7) was obtained from EST collection in Brassica genomics team and its DNA sequence was determined. The cDNA clone is 1,037 bp long in nucleotides and encodes an open reading frame of 307 amino acids. Based on a phylogenetic tree, BrWRKY7 belongs to group IId. BrWRKY7 was induced by wound and SA. It was also induced by pathogen attack such as Xanthomonas campestris pv. campestris (Xcc), suggesting that this BrWRKY may play an essential role in defense response of chinese cabbages.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.857-871
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• 2017

The major substrates used in soilless growing media are peat moss and perlite, where peat moss is a limited and expensive natural resource. Determination of appropriate substrates based on technical and economic feasibility is the vital aspect of research and the key to success in any soilless production system. This research work was performed to evaluate different low-cost and sustainable alternative substrate as soilless growing media for horticulture plant. The objective of this study was to compare the effect of sawdust species and steam treatment, for physico-chemical properties and growth of horticultural plant. This study involves the physical and chemical characterization and growth test of four substrate (pine sawdust, oak sawdust, steamed pine sawdust and steamed oak sawdust) in order to evaluate their use as components of growing media. Steamed oak sawdust ($121^{\circ}C$, 30 min) showed adequate physical and chemical properties compared to peat moss for their use as growing media. The growing media were prepared using different mixture proportion to grow Brassica campestris L., Festuca arundinacea and Lespedeza cyrtobotrya Miq. The highest germination, stem length and leaf area of Brassica campestris L., Festuca arundinacea and Lespedeza cyrtobotrya were observed in 30 minute steamed oak sawdust mixture growing media. The steam treatment condition of sawdust used in the growing media significantly positive affected the germination, the stem length and the leaf area.