• Journal of Plant Biotechnology
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• 제6권4호
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• pp.221-227
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• 2004

Protocol was established for production of virus free healthy seeds using meristem ($0.3-0.5\;\cal{mm}$ in size) culture and field management under net house condition in tomato. The isolated meristem was found well established in MS liquid medium containing $0.1\;\cal{mg}\;1^{-1}\;of\;GA_3$. For shoot and root development either from primary meristem or from nodal segment of meristem derived plants, semisolid MS medium having $0.5\;\cal{mg}\;1^{-1}$ of IBA was found most effective. The elimination of the studied viruses (ToMV, CMV, ToLCV) in meristem-derived plants was confirmed by DAS-ELISA test. For field management of the virus eradicated meristem-derived plants, use of net house was found very effective measures to check viral vector visit and eventually infection. The meristem-derived plants were vigor and high yielder than the native seed derived plants and produced healthy seeds. Due to stop vector visit, no viral symptoms were observed in both $R_1\;and\;R_2$ plants cultivated in net house condition. Starting of viral infestation was observed in $R_2$ generation when they were planted in open house condition without control of vector visit. Therefore, for management of viral diseases, use of virus free meristem derived plantlets and their subsequent cultivation in soil under net house condition without using any vector killing insecticide can be recommended for producing healthy seeds in tomato. The developed protocol for environmentally healthy tomato seed production in Bangladesh may be used in the countries having similar tropical like environment conducive for viral vector visit.

• 한국식물병리학회지
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• 제3권1호
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• pp.3-7
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• 1987

도열병에 대해 감수성을 보이는 낙동과 성체식물저항성을 보이는 도봉의 건전엽과 도열병 감염엽내의 에탄올가용성 아미노산과 페놀화합물을 양적으로 분석하였다. 접종 3일후에는 가용성 아미노산과 페놀화합물의 수준은 건전엽과 비슷하였다. 도열병 병반이 접종 5일 후에 감염엽에 나타났을 때 가용성 아미노산과 페놀화합물은 5엽기와 3엽기에서 증가하기 시작하였고, 접종 7일 후에서는 이들 화합물의 수준은 5엽기와 8엽기에서 건전엽보다 약 $1.5\~3$배 더 많았다. 도열병 감염동안 비록 도봉이 도열병에 대해 낙동보다 덜 감염되었지만 5엽기와 8엽기의 건전엽과 감염엽에서 성체식물저항성 품종 도봉의 가용성 아미노산 및 페놀화합물 함량은 감수성 품종 낙농의 함량보다 높았다. 벼품종 도봉이 도열병에 감염동안 아미노산과 페놀화합물 함량이 현저하게 증가하여 성체식물저항성이 발현하는데 중요한 역할을 할지 모른다.

• The Plant Pathology Journal
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• 제39권2호
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• pp.207-219
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• 2023

Soft rot is a widespread, catastrophic disease caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) that severely damages the production of Amorphophallus spp. This study evaluated the rhizosphere bacterial and fungal communities in Pcc-infected and uninfected plants of two species of Amorphophallus, A. muelleri and A. konjac. Principal component analysis showed that the samples formed different clusters according to the Pcc infection status, indicating that Pcc infection can cause a large number of changes in the bacterial and fungal communities in the Amorphophallus spp. rhizosphere soil. However, the response mechanisms of A. muelleri and A. konjac are different. There was little difference in the overall microbial species composition among the four treatments, but the relative abundances of core microbiome members were significantly different. The relative abundances of Actinobacteria, Chloroflexi, Acidobacteria, Firmicutes, Bacillus, and Lysobacter were lower in infected A. konjac plants than in healthy plants; in contrast, those of infected A. muelleri plants were higher than those in healthy plants. For fungi, the relative abundances of Ascomycota and Fusarium in the rhizosphere of infected A. konjac plants were significantly higher than those of healthy plants, but those of infected A. muelleri plants were lower than those of healthy plants. The relative abundance of beneficial Penicillium fungi was lower in infected A. konjac plants than in healthy plants, and that of infected A. muelleri plants was higher than that of healthy plants. These findings can provide theoretical references for further functional research and utilization of Amorphophallus spp. rhizosphere microbial communities in the future.

• 식물병연구
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• 제18권2호
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• pp.80-85
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• 2012

딸기 '설향' 품종을 대상으로 흰가루병 발생양상 및 건전식물체와 흰가루병 이병식물체 사이의 잎 온도, 광합성, 영양성분 등을 비교분석하였다. 흰가루병 발생은 1월 중순부터 과실에 발병이 시작되어 수확 후기에는 과실과 잎에도 발생되었다. 건전 식물체의 광합성 량과 잎 온도는 흰가루병 감염 식물체보다 높았으며 병 발생이 증가함에 따라 뚜렷하게 감소하였다. 건전 식물체와 이병식물체의 토양분석에서는 영양성분간 유의성이 없었다. 반면, 잎에서는 건전식물체가 이병식물체보다 칼륨 농도는 낮고 망간과 엽록소 함량은 높은 경향을 보였는데, 특히 망간농도가 건전식물체에서 현저하게 높음을 알 수 있었다. 따라서 딸기 잎의 칼륨, 망간, 엽록소 함량은 흰가루병 억제에 중요한 요인이 될 것이다.

• Journal of Plant Biology
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• 제7권1호
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• pp.1-4
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• 1964

A comparative study of free amino acid content in healthy and virus diseased tobacco leaves was carried out by author throughout the gorwing season from June to November of 1963. The methods of qualitative analysis of free amino acids applied in this experiment is followed by Moore and Stein. 1,2 Free amino acids determined in this experiment are shown in Fig. Ⅰ, Ⅱ and Table Ⅰ. As the figure and the table are shown, four more amino acids such as a spartic acid, glutamic acid, tyrosine and phenylalanine are detected in the healthy leaves; these four additional amino acids in the healthy leaves are conspicuous. More quantities of asparagine and alanine are detected in the diseased leaves than the healthy leaves and more quantities of tryptophan is detected in the healthy leaves. It is presumed that such amino acids as tyrosine and phenyllanine are decreased by the incooperation of free amino acid to TMV protein in the process of the process of the leaf protein metabolism which is caused by TMV-RNA trapping action in the diseased leaf protoplasm. It is thought that the decrease of asparagine and the increase of asparic acid in the healthy leaves are the results of in incooperaton of NH2, produced by the protein dissimilation in the diseased leaves, to aspartic acid; it's reaction is caused by the respiration of the diseased leaves accelerated by TMV attack. It is presumed, consequently, that the check of the diseased tobacco leave growth is influenced by the reduction of such amino acids as tryptophane and glutamic acid, which reduction may be due to the abnormal protein metabolism and the action of certain enzyme caused by TMV attack on host protoplast.

• 한국식물병리학회지
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• 제10권1호
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• pp.25-28
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• 1994

One hundred fifty four our of 262 isolates of Fusarium oxysporum obtained from healthy plant tissues of various crops and their rhizosphere soil were found to be nonpathogenic to cucumber plants. The nonpathogenic isolates were frequently found from sesame plant tissues and rhizosphere soil, but less from healthy plant tissues of cucumber and water melon. When the 154 nonpathogenic isolates were preinoculated into cucumber seedlings, and then challenge-inoculated with Fusarium wilt pathogen, 21 isolates protected effectively cucumber plants from Fusarium wilt infections. A year later, 9 out of 21 isolates fully sustained their protective effect. Among 9 isolates showing good protective effects, 7 were isolates from cucumber plants. These 9 isolates except 1 isolate, were not pathogenic to water melon, chines melon, tomato and sesame.

• 한국식물병리학회지
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• 제10권1호
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• pp.29-33
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• 1994

One hundred fifty four out of 262 isolates of Fusarium oxysporum obtained from healthy plant tissues of various crops and their rhizosphere soil were found to be nonpathogenic to cucumber plants. The nonpathogenic isolates were frequently found from sesame plant tissues and rhizosphere soil, but less from healthy plant tissues of cucumber and water melon. When the 154 nonpathogenic isolates were preinoculated into cucumber seedlings, and then challenge-inoculated with Fusarium wilt pathogen, 21 isolates protected effectively cucumber plants from Fusarium wilt infections. A year later, 9 out of 21 isolates fully sustained their protective effect. Among 9 isolates showing good protective effects, 7 were isolates from cucumber plants. These 9 isolates, except 1 isolate, were not pathogenic to water melon, chinese melon, tomato and sesame.

• The Plant Pathology Journal
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• 제40권3호
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• pp.299-309
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• 2024

The rice blast disease, caused by the fungal pathogen, Magnaporthe oryzae (syn. Pyricularia oryzae), poses a significant threat to the global rice production. Understanding how this disease impacts the plant's microbial communities is crucial for gaining insights into host-pathogen interactions. In this study, we investigated the changes in communities of bacterial and fungal endophytes inhabiting different compartments in healthy and diseased plants. We found that both alpha and beta diversities of endophytic communities do not change significantly by the pathogen infection. Rather, the type of plant compartment appeared to be the main driver of endophytic community structures. Although the overall structure seemed to be consistent between healthy and diseased plants, our analysis of differentially abundant taxa revealed the specific bacterial and fungal operational taxonomic units that exhibited enrichment in the root and leaf compartments of infected plants. These findings suggest that endophyte communities are robust to the changes at the early stage of pathogen infection, and that some of endophytes enriched in infected plants might have roles in the defense against the pathogen.

• The Plant Pathology Journal
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• 제39권4호
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• pp.397-408
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• 2023

Fire blight disease, caused by Erwinia amylovora, is a devastating affliction in apple cultivation worldwide. Chemical pesticides have exhibited limited effectiveness in controlling the disease, and biological control options for treating fruit trees are limited. Therefore, a relatively large-scale survey is necessary to develop microbial agents for apple trees. Here we collected healthy apple trees from across the country to identify common and core bacterial taxa. We analyzed the endophytic bacterial communities in leaves and twigs and discovered that the twig bacterial communities were more conserved than those in the leaves, regardless of the origin of the sample. This finding indicates that specific endophytic taxa are consistently present in healthy apple trees and may be involved in vital functions such as disease prevention and growth. Furthermore, we compared the community metabolite pathway expression rates of these endophyte communities with those of E. amylovora infected apple trees and discovered that the endophyte communities in healthy apple trees not only had similar community structures but also similar metabolite pathway expression rates. Additionally, Pseudomonas and Methylobacterium-Methylorobrum were the dominant taxa in all healthy apple trees. Our findings provide valuable insights into the potential roles of endophytes in healthy apple trees and inform the development of strategies for enhancing apple growth and resilience. Moreover, the similarity in cluster structure and pathway analysis between healthy orchards was mutually reinforcing, demonstrating the power of microbiome analysis as a tool for identifying factors that contribute to plant health.

• 식물병연구
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• 제8권4호
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• pp.245-249
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• 2002

검은점뿌리썩음병의 병원균에 감염된 참외의 광합성 및 생육 반응을 측정한 결과, 수확기 참외의 광합성 속도는 이병주가 건전주에 비해 현저하게 낮았고, 기공저항은 이병주에서 큰 것으로 나타났다. 목부일비액은 이병주에서 전혀 분비되지 않았다. 수확기 참외의 잎과 줄기에서 무기양분함량은 이병주와 건전주 간에 차이를 보여주지 않았다. 참외의 생육특성은 이병주가 건전주에 비해 엽면적이나 생체중및 건물중에서 건전주에 비해 낮았으며, 평균 과중도 같은 경향을 보였다.