• 한국식품위생안전성학회지
• /
• 제7권4호
• /
• pp.157-160
• /
• 1992

쑥으로부터 추출한 정유를 Escherichia coli, Bacillus subtilis , Pleurotus ostreatus , Fusarium solani , Aspergillus nidulans에 첨가한 후 배양한 결과 다음과 같은 결과를 얻었다. 쑥의 정유를 첨가한 후 미생물을 배양시킨 결과 Escherichia coli,는 무반응이었으나 Bacillus subtilis , Pleurotus ostreatus , Fusarium solani , Aspergillus nidulans는 생육이 저해되었다. bacillus subtilis는 대조군에 비해 정유의 농도가 10~100ppm에서 10배의 생육저해를 나타냈다. 쑥의 정유는 또한 곰팡이에서 강한 생육저해를 나타냈으며 Pleurotus ostreatus는 1,000ppm의 농도에서 생육이 완전히 정지되었다.

• Mycobiology
• /
• 제30권2호
• /
• pp.96-101
• /
• 2002

Four pathogenic fungal isolates belonging to different genera including Alternaria, Fusarium and Curvularia were isolated from selected diseased weeds growing in the fields in Dakahalia district. The inoculum of these pathogenic fungi specific to weeds were cultured, standardized and formulated as alginate pellets containing mycelium plus culture filtrate. These mycoherbicides were evaluated for disease severity(DS). Maximum DS was obtained with the alginate pellets of mycelium filtrate Fusarium solani. Physiological changes of the treated weed were determined 5 aiid 10 days after treatments. As compared to the healthy weeds, all mycoherbicide formulations significantly decreased the amount of photosynthetic pigments and subsequently soluble and insoluble sugars in the infected weeds. The mycoherbicide formulation of F. solani had the greatest effect on lowering to the abovementioned amount in the leaves of Chenopodium murale. Generally, treatment of weed leaves with the specific mycoherbicide led to a highly significant increase in total phenol content when compared to the healthy control weed. C. murale infected with the mycoherbicide formulation of F. solani had higher levels of phenolic compounds than those other treated weeds particularly after 10 days of inoculation.

• The Plant Pathology Journal
• /
• 제17권1호
• /
• pp.52-56
• /
• 2001

This study was undertaken to separate and identify antifungla substances produced by Gilocladium virens G1, a biocontrol agent used for the control of plant diseases caused by Rhizoctonea solani. The culture of G. virens G1 effectively inhibited the growth of R. solani, Colletotrichum gloeosporioides, and Phytophthora capsici, but less that of Fusarium oxysporum. The n-hexane extract of the G. virens culture, which was used for the purification of responsible substances, strongly inhibited R. solani and C. gloeosporioides, but not P. capsici, although the n-butanol extract was effective on all of the pathogens tested. An antifungal substance was purified using the n-hexane extract by Silica gel column chromatography and HPLC. The substance was examined for purity by HPLC and for nature by UV spectrometry, which differed from known antibiotic compounds such as gliotoxin, viridin and gliovirin. The antifungal substance was very liphophilic based on its solvent-solubility and Rf values on TLC, and more inhibitory to C. gloeosporioides than other fungal pathogens tested.

• 농약과학회지
• /
• 제19권4호
• /
• pp.424-427
• /
• 2015

Rhizoctonia solani에 의해 발생하는 잘록병은 인삼 묘포에서 가장 중요한 병이다. 이 병을 방제하기 위해 사용된 folclofos-methyl은 약 20년간 사용되어 왔다. 이 약제는 6년생 수삼에서도 잔류가 되어 안전하고 병원균 방제에 효과적인 약제를 선발하기 위해 4종 (fludioxonil, flutolanil, pencycuron, thifluzamide)의 살균제의 약효를 검정하였다. 실내에서 시기별로 80% 이상의 생육억제 효과를 조사한 결과, fludioxonil 25일, thifluzamide, flutolanil 10일, pencycuron 1일로 조사되었으며, 포장시험에서 방제효과는 fludioxonil, thifluzamide, flutolanil, Pencycuron에 대해 각각 71%, 57%, 54%, 29%의 효과를 보였다. 가장 높은 효과를 보인 Fludioxonil의 경우 국내 및 해외에 등록되어 있으며, 잔류성 조사 결과 묘삼에서 0.44 mg/kg으로 조사되어 이후 5년간 재배 시 영향이 없을 것으로 조사되었다. 따라서 Fludioxonil은 Tolclofos-methyl을 대체하여 사용할 수 있을 것으로 판단된다.

• 식물병연구
• /
• 제15권1호
• /
• pp.54-56
• /
• 2009

2006년부터 2007년까지 전북 남원시 운봉읍 화훼 재배 농가 단지에서 스타티스 줄기썩음병이 발생하였다. 병징은 지제부 부근의 줄기와 잎이 마르면서 갈색 또는 암갈색으로 변하며, 병이 진전되면 관부까지 갈변하다가 포기 전체 발병하여 고사한다. 병원균은 PDA에서 기중균사를 형성하고, 처음에는 흰색을 띠다가 연한 갈색으로 변하였다. 균사는 $90^{\circ}$로 분지하고, 대부분 하나의 세포에 다핵을 형성하였다. 또한 PDA에서 부정형 또는 타원형으로 $0.3{\sim}0.5\;mm$의 균핵을 형성하였다. 병원성 검정은 코흐의 가설에 따란 수행하여 병원성을 확인하였다. 본 연구에서 스타티스에 줄기썩음을 일으키는 병원균의 균학적 특징 및 형태적 특징을 조사한 결과, Rhizoctonia solani에 의한 스타티스 줄기썩음병으로 명명하고자 제안한다.

• 식물병연구
• /
• 제13권1호
• /
• pp.6-14
• /
• 2007

2005년과 2006년에 걸쳐 경기도 남양주의 호접란(Phalaenopsis spp.), 풍란(Neofinetia falcata), 나도풍란(Aerides japonicum)을 재배하고 있는 온실재배농가에서 뿌리 및 줄기기부 썩음 증상이 발생되었다. 이들 난은 초기에는 시들음 증상을 나타내고 병든 개체의 잎들은 황화되거나 붉게 변하며 낙엽되고 결국 고사하였다. 병든 개체의 뿌리 및 하엽으로부터 59개 Furaium spp.를 분리하여 동정 한 결과 F. oxysporum, F. proliferatum, F. solani 3종으로 동정되었다. 이 중 F. oxysporum, F. proliferatum은 호접란과 풍란류에서 모두 분리되었고, F. solani는 호접란에서만 분리되었다. 병원성실험 결과 이들 3종 모두 병원성이 인정되었다. 비록 F. oxysporum, F. proliferatum, F. solani은 호접란에 대하여 뿌리썩음병원균으로 보고되어 있으나 풍란과 나도풍란에 대해서는 아직 보고된 바 없다. 따라서 본 연구를 통해 F. oxysporum, F. proliferatum에 의한 풍란과 나도풍란의 뿌리 및 줄기썩음병을 처음 보고하는 바이다.

• 한국식물병리학회지
• /
• 제11권1호
• /
• pp.1-8
• /
• 1995

Alternaria alternata and A. solani were identified from 130 Alternaria isolates obtained from red pepper fruits, and three species including A. alternata, A. sesami and A. sesamicola were detected from 150 isolates from sesame seeds. Among the 4 Alternaria species, A. alternata was the predominant fungus from both plants, having incidence of 95.4% in red pepper and 56.0% in sesame. Of the total 280 isolates, cultures on autoclaved rice of 75 isolates were tested for toxicity to 21-day-old virgin female rats. Out of 50 isolates of A. alternata, 17 were lethal to rats, inducing congestion and hemorrhage of stomach and intestine and kidney enlargement, and 8 caused lack of weight gain or weight loss. The other 25 isolates of A. alternat and all the isolates of A. sesami, A. sesamicola and A. solani, showed no significant indication of toxicity. Production of mycotoxins in the rice cultures of the above 75 isolates belonging to 4 species was analyzed. Alternaria cultures were extracted with methanol and purified by using solvent partition, thin-layer chromatography, and high performance liquid chromatography. Of the four species tested, all produced alternariol (AOH) and alternariol monomethyl ether (AME), three (A. alternata, A. sesami and A. sesamicola) produced alternuene (ALT) and altertoxin-I (ATX-I), and only A. alternata produced tenuazonic acid (TA). TA was produced by all of the highly toxic (lethal to rats) isolates of A. alternata, but not by any nontoxic isolates.

• The Plant Pathology Journal
• /
• 제21권3호
• /
• pp.275-282
• /
• 2005

A chitinolytic bacterium, Chromobacterium sp. strain C-61, was found strongly antagonistic to Rhizoctonia solani, a causal agent of damping-off of eggplant. In this study, the biocontrol activity and enzymatic characteristics of strain C-61 were compared with its four Tn5 insertion mutants (C61-A, -B, -C, and -D) that had lower chitinolytic ability. The chitinase activity of a 2-day old culture was about $76\%,\;49\%\;and\;6\%$ level in C61-A, C61-B and in C61-C, respectively, compared with that of strain C-61. The $\beta-N-acetylhexosaminidase$(Nahase) activity was little detected in strain C-61 but increased largely in C-61A, C61-B and C61-C. Activities of chitinase and Nahase appeared to be negatively correlated in these strains. Another mutant, C-61D, produced no detectable extracellular chitinase and Nahase. The in vitro and in vivo biocontrol activities of strain C-61 and its mutants were closely related to their ability to produce chitinase but not Nahase. No significant differences in population densities between strain C-61 and its mutants were observed in soil around eggplant roots. The results of SDS-PAGE and isoelectrofocusing showed that a major chitinase of strain C-61 is 54-kDa with pI of approximately 8.5. This study provides evidence that the biocontrol activity of Chromobacterium sp. strain C-61 against Rhizoctonia solani depends on the ability to produce chitinase with molecular weight of 54-kDa and pI of 8.5.

• The Plant Pathology Journal
• /
• 제37권4호
• /
• pp.315-328
• /
• 2021

Fusarium and Rhizoctonia genera are important pathogens of many field crops worldwide. They are constantly evolving and expanding their host range. Selecting resistant cultivars is an effective strategy to break their infection cycles. To this end, we screened a collection of Medicago truncatula accessions against Fusarium oxysporum, Fusarium solani, and Rhizoctonia solani strains isolated from different plant species. Despite the small collection, a biodiversity in the disease response of M. truncatula accessions ranging from resistant phenotypes to highly susceptible ones was observed. A17 showed relative resistance to all fungal strains with the lowest disease incidence and ratings while TN1.11 was among the susceptible accessions. As an initiation of the characterization of resistance mechanisms, the antioxidant enzymes' activities, at the early stages of infections, were compared between these contrasting accessions. Our results showed an increment of the antioxidant activities within A17 plants in leaves and roots. We also analyzed the responses of a population of recombinant inbred lines derived from the crossing of A17 and TN1.11 to the infection with the same fungal strains. The broad-sense heritability of measured traits ranged from 0.87 to 0.95, from 0.72 to 0.96, and from 0.14 to 0.85 under control, F. oxysporum, and R. solani conditions, respectively. This high estimated heritability underlines the importance of further molecular analysis of the observed resistance to identify selection markers that could be incorporated into a breeding program and thus improving soil-borne pathogens resistance in crops.

• Mycobiology
• /
• 제28권4호
• /
• pp.185-189
• /
• 2000

The antifungal activity of methanolic extracts of Centella asiatica and Andrographis paniculata leaves was observed against fourteen fungi, viz., Alternaria alternata, A. brassicae, A. brassicicola, A. solani, A. tenuissima, Cercospora blumae, Curvularia lunata, C. penniseti, and Drechslera monoceras, D. oryzae, D. turitica, Fusarium albizziae and F. udum. Different concentrations of the methanolic extract (1000, 2000, 3000, 5000, 7000, 10000ppm) were used. The effect of mixed leaf extract (1500 ppm of C. asiatica + 1500 ppm of A. paniculata) and its 1:2 ad 1:4 dilutions were also studied. The individual extracts of both the plants showed significant inhibitory effect on spore germination of all the fungi tested. F. udum, F. albizzae, D. oryzae, D. turtica, and D. monoceras were particularly sensitive to these extracts. In general, the extract of C. asiatica showed a higher inhibitory effect in all concentrations against all the fungi as compared to A. paniculata, except for A. brassicae A. solani, D. oryzae, D. penniseti and Curvularia sp. The inhibitory effect of extracts increased when they were used in combination with or without dilutions against A. brassicicola, A. solani A. brassicae, A. alternata, A. tenussima, C. blumae, C. lunata, C. penniseti and Curvularia species. Higher efficacy of active ingredient of these extracts under field condition is envisaged against plant pathogens.