• 미생물학회지
• /
• 제21권4호
• /
• pp.213-220
• /
• 1983

Conditions for isolation of protoplasts from conidiospores of Trichoderma koningii ATCC 26113 were tested. Maximum production of conidial protoplasts was obtained by preincubation of conidiospores on liquid minimal medium for 8 1/2 hrs. and by reaction with cell wall lytic enzyme for 3 hrs. Among effective cell wall lytic enzymes (Driselase, p-Glucuronidase, Novozyme and Zymolyase), Driselase was the most effective one on the production of conidial protoplasts. The production of conidial protoplasts was also enhanced by addition of 2-Deoxy-D-Glucose $(25{\mu}g/ml)$ into liquid minimal medium. Over 70% of the initial swollen conidia, preincubated in liquid minimal medium supplemented with 2-Deoxy-D-Glucose $(25{\mu}g/ml)$, were converted to protoplasts by incubation with 2% (w/v) commercial lytic enzyme Driselase at $28^{\circ}C$ for 3 hrs. The reversion frequency of the conidial protoplasts was about 30 times (25-50%) higher than that of mycelial protoplasts (0.6-1.3%).

• 한국응용곤충학회지
• /
• 제1권
• /
• pp.26-28
• /
• 1962

도열병균의 분생포자를 다량으로 형성하는 배지를 찾고자 여러 가지 영양분을 차진 한천 및 액체배지에 대하여 분생포자형성도를 시험하였다. 여러 가지 공시 배지 중에서 V-8배양액과 토마토 즙한천배지 상에서 가장 많은 분생포자가 형성되었고, 볏짚배지 상에서 가장 적은 수의 분생포자카 형성되였다. 이와 같이 V-8즙배양액화 토마토한천배지는 도열병균 분생포자형성도에 있어서 과거 연구자들이 최적이라고 보고한 쌀겨한천배지와 효모전분한천배지를 훨씬 능가하였다.

• Mycobiology
• /
• 제49권3호
• /
• pp.258-266
• /
• 2021

The velvet regulators VosA and VelB are primarily involved in spore maturation and dormancy. Previous studies found that the VosA-VelB hetero-complex coordinates certain target genes that are related to fungal differentiation and conidial maturation in Aspergillus nidulans. Here, we characterized the VosA/VelB-inhibited developmental gene vidD in A. nidulans. Phenotypic analyses demonstrated that the vidD deleted mutant exhibited defect fungal growth, a reduced number of conidia, and delayed formation of sexual fruiting bodies. The deletion of vidD decreased the amount of conidial trehalose, increased the sensitivity against heat stress, and reduced the conidial viability. Moreover, the absence of vidD resulted in increased production of sterigmatocystin. Together, these results show that VidD is required for proper fungal growth, development, and sterigmatocystin production in A. nidulans.

• 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.

• Journal of Plant Biology
• /
• 제6권1호
• /
• pp.8-10
• /
• 1963

1. 한천배양기상에서의 토마토즙함량과 사탕무 갈반병균 Cercospora beticola 의 포자형성도와의 관계를 조사하였다. 2. 감자즙한천배양기상에서 포자를 형성하지 않는 배양균 C. beticola는 토마도즙을 10% 이상 함유하고 있는 한천배양기상에서 이식후 48시간만에 포자를 형성하였다. 3. 토마도즙을 10% 함유하고 있는, 한천배양기상에서는 극히 소수의 포자가 형성되었으나, 토마도즙 함량이 20% 이상인 한천배양기상에서는 다수의 포자가 형성되었고, 한천배양기상의 토마도즙함량이 높을수록 더 많은 포자가 형성되었다.

• The Plant Pathology Journal
• /
• 제18권1호
• /
• pp.50-53
• /
• 2002

To develop Epicoccosorus nematosporus as a mycoherbicide of Eleocharis kuroguwai, the optimum temperature and humidity for sporulation of the pathogen were studied. Conidial production was most abundant at $28^{\circ}C$ with RH 60%, which yielded 661 mg in 9 cm Petri dish. Light intensity of 3,000 up to 7,500 lux was effective in stimulating conidial production of E. nematosporus on oatmeal agar, Light intensity affected sporulation more significantly than temperature. In the pot test, at least 12 h of dew period at $20^{\circ}C$ and $25^{\circ}C$ was required to achieve satisfactory conidial germination and appressorial formation. Few were killed at 8 h of dew period regardless of temperature. Sixteen hours of a single dew treatment immediately after inoculation killed more plants than did two or three repetitive dew treatments of 8-12 h.

• Mycobiology
• /
• 제38권1호
• /
• pp.13-16
• /
• 2010

A specimen of Beauveria bassiana was collected from Yang-yang of Gangwon province, Korea in October 2006. Conidial isolates were prepared from the specimen by the dilution method and inoculated in brown rice medium for fruiting body production. After nearly two months incubation for perithecial stromata developed from single isolates as well as from their combinations. They were determined as Cordyceps bassiana by observing the stromatal characters and their conidial structures. This is the first report of the development of C. bassiana from B. bassiana cultures.

• 식물병연구
• /
• 제24권4호
• /
• pp.292-301
• /
• 2018

Alternaria leaf spot disease has been a concern during a tomato production in greenhouse. In vitro antifungal activities of vapours of four plant essential oils, cinnamon oil, fennel oil, origanum oil and thyme oil, were investigated during in vitro conidial germination and mycelial growth of Alternaria alternata causing the tomato leaf spots to find eco-friendly alternatives for chemical fungicides. The four plant essential oils showed different antifungal activities against in vitro conidial germination of A. alternata in dose-dependent manners, and cinnamon oil vapour was most effective to suppress the conidial germination. The four plant essential oils showed similar antifungal activities against the in vitro mycelial growth of A. alternata in dose-dependent manners, but low doses of thyme oil vapour slightly increased in vitro mycelial growth of A. alternata. Necrotic lesions on the A. alternata-inoculated tomato leaves were reduced differently depending on kinds and concentrations of plant essential oils. Delayed conidial germination and germ-tube elongation of A. alternata were found on the tomato leaves treated with cinnamon oil and origanum oil vapours at 6 hpi. These results suggest that volatiles from cinnamon oil and origanum oil can be provided as alternatives to manage Alternaria leaf spot during the tomato production eco-friendly.

• The Plant Pathology Journal
• /
• 제32권5호
• /
• pp.388-395
• /
• 2016

The most serious aerial disease of garlic is leaf blight caused by Stemphylium spp. Geographical variation in the causal agent of this disease is indicated. Stemphylium vesicarium has been reported in Spain, whereas S. solani is the most prevalent species recorded in China. In this study, Stemphylium isolates were obtained from symptomatic garlic plants sampled from the main Spanish production areas. Sequence data for the ITS1-5.8S-ITS2 region enabled assignation of the isolates to the Pleospora herbarum complex and clearly distinguished the isolates from S. solani. Conidial morphology of the isolates corresponded to that of S. vesicarium and clearly discriminated them from S. alfalfae and S. herbarum on the basis of the size and septation pattern of mature conidia. Conidial morphology as well as conidial length, width and length:width ratio also allowed the Spanish isolates to be distinguished from S. botryosum and S. herbarum. Control of leaf blight of garlic is not well established. Few studies are available regarding the effectiveness of chemical treatments to reduce Stemphylium spp. incidence on garlic. The effectiveness of nine fungicides of different chemical groups to reduce Stemphylium mycelial growth in vitro was tested. Boscalid + pyraclostrobin (group name, succinate dehydrogenase inhibitors + quinone outside inhibitors), iprodione (dicar-boximide), and prochloraz (demethylation inhibitors) were highly effective at reducing mycelial growth in S. vesicarium with $EC_{50}$ values less than 5 ppm. In general, the effectiveness of the fungicide was enhanced with increasing dosage.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2014년도 추계학술대회 및 정기총회
• /
• pp.13-13
• /
• 2014

Species belonging to the genus Fusarium are widely distributed and cause diseases in many plants. Isolation of fungal strains from air or cereals is necessary for disease forecasting, disease diagnosis, and population genetics [1]. Previously we showed that Fusarium species are resistant to toxoflavin produced by the bacterial rice pathogen Burkholderia glumae while other fungal genera are sensitive to the toxin, resulting in the development of a selective medium for Fusarium species using toxoflavin [2]. In this study, we have tried to elucidate the resistant mechanism of F. graminearum against toxoflavin and interaction between the two pathogens in nature. To test whether B. glumae affects the development of F. graminearum, the wild-type F. graminearum strains were incubated with either the bacterial strain or supernatant of the bacterial culture. Both conditions increased the conidial production five times more than when the fungus was incubated alone. While co-incubation resulted in dramatic increase of conidial production, conidia germination delayed by either the bacterial strain or supernatant. These results suggest that certain factors produced by B. glumae induce conidial production and delay conidial germination in F. graminearum. To identify genes related to toxoflavin resistance in F. graminearum, we screened the transcriptional factor mutant library previously generated in F. graminearum [3] and identified one mutant that is sensitive to toxoflavin. We analyzed transcriptomes of the wild-type strain and the mutant strain under either absence or presence of toxoflavin through RNAseq. Expression level of total genes of 13,820 was measured by reads per kilobase per million mapped reads (RPKM). Under the criteria with more than two-fold changes, 1,440 genes were upregulated and 1,267 genes were down-regulated in wild-type strain than mutant strain in response to toxoflavin treatment. A comparison of gene expression profiling between the wild type and mutant through gene ontology analysis showed that genes related to metabolic process and oxidation-reduction process were highly enriched in the mutant strain. The data analyses will focus on elucidating the resistance mechanism of F. graminearum against toxoflavin and the interaction between the two pathogens in rice. Further evolutionary history will be traced through figuring out the gene function in populations and in other filamentous fungi.