• 한국식물병리학회지
• /
• 제11권3호
• /
• pp.245-251
• /
• 1995

Nine hundred and ninety-two isolates of Botrytis cinerea were obtained from infected strawberries, tomatoes and cucumbers in Taejon, Gongju, Puyo, Nonsan and Kimhae in Korea. Six hundred forty-two (64.7%) isolates were benomyl resistant (BR), 245 (24.7%) were procymidone resistant (PR), and 105 (10.6%) were dichlofluanid resistant (DR). In the minimum inhibitory concentration (MIC) test, DR isolates showed mycelial growth on the PDA incorporated with 100 or 500 $\mu\textrm{g}$/ml of dichlofluanid, while dichlofluanid sensitive (DS) isolates did not grow on the PDA incorporated even with 10 $\mu\textrm{g}$/ml of dichlofluanid. Chemical concentrations for inhibition of spore germination were much lower than those for inhibition of mycelial growth. IC50 values, the effective concentrations for 50% inhibition of spore germination, for DR were 0.11~0.29 $\mu\textrm{g}$/ml, whereas they were 0.04~0.09 $\mu\textrm{g}$/ml for DS isolates. In comparison of fitness-related characteristics such as virulence, sclerotial formation, and sporulation, DR isolates were inferior to DS isolates. However, mycelial growth was little different between DR isolates and DS isolates.

• The Plant Pathology Journal
• /
• 제24권1호
• /
• pp.52-57
• /
• 2008

Twenty isolates of Bacillus spp. obtained from livestock manure composts and cotton-waste composts were tested for in vitro antagonistic effects against soilborne plant pathogenic fungi, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani AG-4, and Sclerotinia sclerotiorum. Seven isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of F. oxysporum tested. The bacterial isolate RM43 was the most effective to inhibit the mycelial growth of the fungal isolates. Twelve isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of P. capsici tested. The bacterial isolates M34 and M47 were very effective to inhibit the mycelial growth of the fungal isolates. Thirteen isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of R. solani AG-4 tested. The bacterial isolates M27 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. Fourteen isolates of Bacillus sp. had antagonistic effects on mycelial growth of all the isolates of S. sclerotiorum tested. The bacterial isolates M49 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. The antagonistic effects of most Bacillus spp. isolates against the isolates of the four fungi differed depending on the fungal species and the isolates of each fungus. The bacterial isolates M27 and M75 were the most effective to inhibit the mycelial growth of all four fungi.

• 한국균학회지
• /
• 제47권3호
• /
• pp.219-232
• /
• 2019

Chemicals related to hydrogen peroxide ($H_2O_2$) and nitric oxide (NO) generations were exogenously applied to Fusarium oxysporum f. sp. fragariae (Fof) causing Fusarium wilt disease in strawberry plants, and regulations of in vitro conidial germination and mycelial growth of the fungus by the chemical treatments were evaluated. $H_2O_2$ drastically reduced the conidial germination of Fof in a dose-dependent manner, and treatment with 3-amino-1,2,4-triazole (3-AT) catalase inhibitor also led to dose-dependent inhibition of conidial germination but relatively moderately. Gradual decreases in mycelial growth of Fof were found by high concentrations of $H_2O_2$, whilst exogenous 3-AT slightly increased the mycelial growth. Increasing sodium nitroprusside (SNP) NO donor, $N^G$-nitro-l-arginine methyl ester (L-NAME) NO synthase (NOS)-inhibitor and tungstate nitrate reductase (NR) inhibitor led to dose-dependent reductions in conidial germination of Fof in quite different levels. SNP conversely increased the mycelial growth but increasing L-NAME moderately decreased the mycelial growth. Tungstate strongly enhanced mycelial growth. Differentially regulated in vitro mycelial growths of Fof were demonstrated by SNP, L-NAME and tungstate with or without $H_2O_2$ supplement. Superoxide anion production was also regulated during the mycelial growth of Fof by nitric oxide. These results show that $H_2O_2$ and NO-associated enzymes can be suggested as fungal growth regulators of Fof as well as eco-friendly disease-managing agents in strawberry production fields.

• Mycobiology
• /
• 제49권5호
• /
• pp.498-506
• /
• 2021

An endophytic fungus strain DYSJ3 was isolated from a stem of Aphanamixis grandifolia Blume, which was identified as Aspergillus versicolor based on the morphological characteristics, internal transcribed spacer (ITS) and calmodulin gene sequences analyses. A. versicolor DYSJ3 exhibited strong antagonistic activity against Colletotrichum musae, C. gloeosporioides and Fusarium oxysporum f. sp. cubense with the inhibition rates of 61.9, 51.2 and 55.3% respectively. The antifungal metabolites mainly existed in the mycelium of A. versicolor DYSJ3, and its mycelial crude extract (CE) had broad-spectrum antifungal activities against plant pathogenic fungi. The CE had a good thermal stability, and the inhibition rate of 100 mg/mL CE against C. musae was above 70.0% after disposing at 120 ℃ for 1 h. Five secondary metabolites were isolated from the CE and identified as averufanin, ergosterol peroxide, versicolorin B, averythrin and sterigmatocystin. Activity evaluation showed versicolorin B exhibited inhibitory effects on the mycelial growth and conidial germination of C. musae, and sterigmatocystin had a weak inhibitory effect on the mycelial growth of C. musae.

• 한국응용곤충학회지
• /
• 제5_6권
• /
• pp.65-69
• /
• 1968

본 실험에 있어서는 phenylmercuric acetate에 못지 않은 살균력을 나타낸다고 보고된 phenylemercuric 8-oxyquinolinate를 phenylmercuric acetate 와 대비시켜 벼 고마엽고병균 에 대하여 먼저 균체의 건물량에 의한 균사발육 효과를 확인하고 포자 및 균사의 호흡 저해효과를 검토한 바 그 결과를 보고하는 바이다. (1) 균사발육 억제효과를 보면 phenylmercuric 8-oxyquinolinate는 phenylmercuric acetate보다 약간 떨어지나 현저한 차이는 없으며, 양자 모두 0.01ppm부터 1.0ppm까지의 사이에서 급격히 발육 억제효과가 증가한다. (2) 포자효흡 저해작용은 0.1ppm을 제외하고는 phenylmercuric acetate가 phenylmercuric 8-oxyquinolinate보다 약간 강하나 뚜렷한 차이는 인정할 수 없으며 0.01ppm에서는 거의 저해효과가 없는 듯하다. (3) 균사호흡 저해작용은 포자호흡과는 반대로 phenylmercuric 8-oxyquinolinate 가 phenylmercuric acctate 보다 강하며, 또한 그 차도 커서 약 $10\%$쯤 된다. (4) 이상의 결과로 미루어 보아 phenylmercuric 8-oxyquinolinate의 포자발아 억제효과는 phenylmercuric acetate와 동정도이거나 약간 높으며, 균사발육 억제효과는 phenylmercuric acetate보다 낮음이 명백하다.

• 한국자원식물학회지
• /
• 제31권6호
• /
• pp.695-703
• /
• 2018

Previously, we have reported a plant extract isolated from Lysimachia foenum gracum Herba as a new environment friendly biopesticide that has the mycelial growth inhibition effect on Magnaporthe oryzae, the pathogenic fungus of the rice blast disease. For the finding of additional biopesticide candidate, we tested the mycelial growth inhibitory effects about 700 species of plant extracts on PDA media. Among them, the extract of Anemarrhena asphodeloides showed prominent inhibitory effect of which $IC_{50}$ was $139.7{\mu}g/ml$. Mycelial radii of M. oryzae were measured on PDA medium containing the four organic solvent fractions isolated from total extract from A. asphodeloides. Ethyl acetate fraction showed the impressive inhibitory effect of $IC_{50}$, $54.12{\mu}g/ml$. In the subsequent rice field test for the total extract of A. asphodeloides, we obtained encouraging 62.0% control rate of rice blast disease without any phytotoxicity. It is almost equivalent to that of chemical pesticides implying the applicability of the extract as a new biopesticide. In further study, the analysis of active ingredients of the extract would be necessary for the development of a new biopesticide and for the verification of cellular mechanism by which the mycelial growth of M. oryzae inhibited.

• 한국식물병리학회지
• /
• 제1권1호
• /
• pp.56-60
• /
• 1985

본 실험은 질소 및 탄소원이 Cercospora kikuchii 균사생장에 미치는 영향과 여러 배양조건에서 생장한 C. kikuchii가 세균생장을 저지하는 정도를 알아보았다. C. kikuchii 균사생장에 적합한 질소원은 yeastextract였고, 탄소원으로는 sucrose, glucose, maltose, fructose를 첨가하였을 때 균사생장이 좋았다. C. kikuchii의 세균생장저지 실험에서 wild type은 pH 조건은 5.0에서, 질소원으로는 yeast-extract 또는 peptone.을 첨가하였을 때, 탄소원으로는 sucrose, maltose, glucose, fructose를 첨가한 배지에서 생장하였을 때 Erwinia carotovora와 Pseudomonas solanacearum의 생장을 크게 저지시켰다. 그러나 albino 돌연변이균주는 실허된 세균의 생장을 거의 저지시키지 못하였다.

• Applied Biological Chemistry
• /
• 제40권5호
• /
• pp.447-450
• /
• 1997

18 종의 N-치환 phenyl 1,3,5-trimethylpyrazole-4-carboxamide 를 합성하여 벼 잎집무늬 마름병균 Rhizoctonia solani $K{\ddot{u}}hn$ 에 대한 균사생육억제력 $(pEC_{50})$ 과 이 균에서 분리한 succinate dehydrogenase (SDH)의 효소활성 저해력 $(pI_{50})$ 을 측정하였다. 구조-활성 상관연구를 통해 균사생육억제력이 SDH 효소저해력과 소수성인자인 chromatographic capacity factor $(\acute{k})$ 에 의해 79%까지 유의성 있게 해석되었으며 이는 합성한 화합물의 주작용점이 SDH 이고 생체내에서 작용점까지 도달하는데 필요한 소수성성질이 살균력의 발현에 중요한 인자임을 보여준다.

• 한국식품과학회지
• /
• 제44권5호
• /
• pp.634-637
• /
• 2012

딸기병해는 생육기 동안 과실의 생산량감소 및 품질저하를 가져오고 있으며, 약제방제의 어려움 등으로 인해 친환경적인 병해 방제법의 개발이 요구된다. 실내에서 자외선(UV-C, 264 nm)조사에 의한 딸기병원균의 균사생장 억제효과를 구명하기 위하여 5종의 딸기병원균을 자외선을 조사하면서 $25^{\circ}C$ 항온실에서 배양한 후 균총의 직경을 측정하였다. 5종의 딸기병원균을 PDA 상에서 배양하면서 자외선을 조사하면, 하루 1시간 조사에 의해서도 생장이 억제되었고 9-12시간을 조사한 균의 생육은 현저하게 억제되었으며 역병균은 생육이 완전하게 억제되었다. 자외선광원과 병원균의 거리에서는 40-50 cm의 거리에서 자외선을 조사한 배양기에서 병원균생장의 억제효과가 크게 나타났다. 배지에 접종한 후 바로 자외선을 처리한 병원균은 모두 2일간 배양한 후 자외선을 접종한 배양기에서보다 생육이 억제되었다. 딸기 탄저병균(C. gloeosprioides)과 시들음병균(F. oxysporum)은 V8A에서 자외선에 의한 균의 생장억제효과가 큰 것으로 나타났다.

• 식물병연구
• /
• 제29권2호
• /
• pp.145-157
• /
• 2023

2018년, 경상북도 청송군 소재 7개의 읍면리의 13개 사과과원에서 채집한 탄저병 감염 과실로부터 39개 탄저병 균주를 분리한 후 이 균주들을 대상으로 국내에 등록된 12개의 사과 탄저병 살균제에 대한 균자생장 억제, 포자발아 억제율을 조사하여 각각의 살균제에 대한 감수성 정도를 한천희석법을 이용한 실내검정법으로 조사하였다. 살균제 감수성 실내검정 결과 captan, dithanon, fluazinam, metconazole, tebuconazole에서는 저항성 균주가 나타나지 않았으나, trifloxystrobin, kresoxim-methyl 살균제에서는 모든 지역에서 저항성을 보이는 균주가 관찰되었다. 이를 통해 일부 지역에서 살균제의 지속적인 처리로 인하여 균주 집단 내 살균제 내성이 발현되었음을 알 수 있었다. 저항성이 발현된 strobilurin 계통의 살균제를 관리하기 위하여 연용 살포를 하지 말아야 하며, 살포기간에 유용미생물로 인한 대체 살포 등 관리가 필요하다.