• The Korean Journal of Mycology
• /
• v.42 no.4
• /
• pp.282-288
• /
• 2014

In this study, we attempted to isolate fungi from soybean fermented foods produced in Sunchang County and to identify Aspergillus oryzae from fungal isolates. Ten fungal isolates were identified with ${\beta}$-tubulin gene. According to the sequences of ${\beta}$-tubulin gene, ten fungal isolates were identified as A. oryzae/flavus complex. For further identification of the ten of fungal isolates, omtA gene, one gene of the aflatoxin biosynthesis gene cluster, was sequenced and the sequences were compared with those of A. oryzae and A. flavus strains from the GenBank database. In addition, identification of the ten fungal isolates was further confirmed using the PCR amplicon of norB and cypA intergenic region, in which a deletion was recognized relative to A. flavus and A. parasiticus. The amplicon size of the ten fungal isolate strains was smaller than those of A. flavus and A. parasiticus, but the same as that of the reference A. oryzae strain. These results indicated that the ten isolates should be identified as A. oryzae. The protease activity in rice koji made with 6, 13, 17, 27, 37 and 38 of strain, respectively was twice higher than that in control. The kojis made with nine of the A. oryzae isolates, respectively, did not produce aflatoxin, suggesting that the strains could possibly be used as starters for soybean products.

• Research in Plant Disease
• /
• v.23 no.2
• /
• pp.150-158
• /
• 2017

Pear scab caused by Venturia nashicola has been reported as an important disease of pear resulting in lowering the quality of pear fruits. In this study, it was conducted to investigate the relationship between resistance of V. nashicola and mutation of ${\beta}$-tubulin gene and the fungicide resistance in field isolate group in benzimidazole fungicides. Responce of V. nashicola to carbendazim could be classified into 3 groups as sensitive that does not grow at all on PDA amended with $0.16{\mu}g/ml$ of carbendazim, low resistance that could not grow in $4.0{\mu}g/ml$ medium, and high resistance that can grow even at $100{\mu}g/ml$. Thirty isolates of V. nashicola collected from 3 regions as Wonju, Naju, and Okcheon were highly resistant to carbendazim. Analysis of the nucleotide sequence of ${\beta}$-tubulin gene of V. nashicola showed that there was no difference in the nucleotide sequence between the sensitive and the low-resistant isolate, but GAG at codon 198 (glutamic acid) was replaced with GCG (alanine) in the high-resistant isolate. Among 10 isolates obtained from the Okcheon, 5 isolates showed the substitution of glycine for glutamic acid, which were resistant to carbendazim, but more sensitive to the mixture of carbendazim and diethofencarb than others. Through these results, all isolates of V. nashicola isolated in pear orchard were found to be resistant to benzimidazoles. Also, mutants E198A and E198G at ${\beta}$-tubulin were found to be important mechanisms of V. nashicola resistance against benzimidazole fungicides.

• Parasites, Hosts and Diseases
• /
• v.47 no.3
• /
• pp.287-291
• /
• 2009

The ${\alpha}/{\beta}$-tubulin heterodimer is the basic subunit of microtubules in eukaryotes. Polyclonal antibodies specific to recombinant ${\alpha}$-tubulin of Giardia lamblia were made, and found effective as a probe to specifically detect G. lamblia by immunofluorescence assays. Nucleotide sequences of ${\alpha}$-tubulin genes were compared between G. lamblia WB and GS strains, prototypes of assemblage A and assemblage B, respectively. A set of primers was designed and used to amplify a portion of the ${\alpha}$-tubulin gene from G. lamblia. PCR-RFLP analysis of this ${\alpha}$-tubulin PCR product successfully differentiated G. lamblia into 2 distinct groups, assemblages A and B.Theresults indicate that ${\alpha}$-tubulin can be used as a molecular probe to detect G.lamblia.

• The Plant Pathology Journal
• /
• v.25 no.4
• /
• pp.322-327
• /
• 2009

A total of 23 isolates of Botrytis cinerea causing the grey mold were collected from infected ginseng in several fields of Korea. The sensitivity to carbendazim and the mixture of carbendazim plus diethofencarb was determined through a mycelial inhibition test on PDA amended with or without fungicides. B. cinerea isolates were classified as 3 phenotypes, which were the first phenotype resistant to both of carbendazim and the mixture ($Car^RMix^R$), the second one resistant to carbendazim and sensitive to the mixture ($Car^RMix^S$), and the last one sensitive to both of them ($Car^RMix^S$). Carbendazim resistance correlated with a single mutation $\beta$-tubulin gene of B. cinerea amplified with primer pair tubkjhL and tubkjhR causing a change of glutamate to alanine at amino acid position 198. Furthermore, the substitution of valine for glutamate led the resistance to carbendazim and the mixture at the same position of amino acid. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis using the restriction endonuclease, Tsp451 and BstUI allowed differentiation of the PCR fragment of $\beta$-tubulin gene of $Car^SMix^S$ isolates from that of $Car^RMix^R$ and $Car^RMix^S$ isolates. This method will aid in a fast detection of resistance of carbendazim and the mixture of carbendazim plus diethofencarb in B. cinerea in ginseng field.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2002.11a
• /
• pp.99.2-99
• /
• 2002

• Mycobiology
• /
• v.37 no.4
• /
• pp.251-257
• /
• 2009

We isolated and identified a strain of Eurotium rubrum from Meju that has not been reported in Korea. This fungus is yellowish brown; reverse dark brown on CYA and PDA while yellow on 2% MEA at $25{^{\circ}C}$. Cleistothecia are first bright yellow and gradually turned brown. Mycerial growth on CYA attained a diameter of 30 mm at $20{^{\circ}C}$, 37 mm at $25{^{\circ}C}$ and 32 mm at $30{^{\circ}C}$ after 15 days. The isolate grew slower on 2% MEA ($<$ 20 mm 15 days at $25{^{\circ}C}$) compared to CYA and PDA ($<$ 40 mm 15 days at $25{^{\circ}C}$). Cleistothecia are superficial, yellow to light brown, globose to subglobose, 40~75 ${\mu}m$ in diameter. Asci are 8-spored and globose to subglobose 8~11 ${\mu}m$. Ascospores are disciform, 4.0~5.0 ${\mu}m$ in length and 4.2~4.5 ${\mu}m$ in width. Conidia are ovate or bacillar, finely roughened to densely spinulose, 4.6~6.0 ${\mu}m$ in length and 3.0~4.3 ${\mu}m$ in width. Compared to known Eurotium rubrum, the Korean isolate showed 99% sequence similarity in ITS rDNA (554 bp) and calmodulin (750 bp) gene and 100% in $\beta$-tubulin (1016 bp) gene. The E. rubrum isolate also had weak $\beta$-glucosidase and protease activities.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.115.1-115
• /
• 2003

Post-harvest decay, caused by Penicillium spp. is a serious problem of fruits worldwide. Morphological characteristics and molecular markers were used to characterize 22 Penicillium isolates from apples, 18 isolates from pears, 60 from oranges and 18 from grapes and 23reference isolates representing related Penicillium spp. to assess their diversity and resolve their taxonomy. Based on morphological and physiological characteristics, the isolates were grouped as identical or very similar to P. digitatum, P. italicum, P. ulaiense or very similar to P. crustosum, P. expansum, P. solitum and unidentified Penicillium spp. Based on sequence comparisons of ITS region, variable site were presented within and among the species, but there variation were not correlated with the species. Cluster analyses of AP-PCR fragment patterns using UP and L45 primer and the -tubulin gene sequence, the Penicillium species were segregated into distinct groups. Particularly. the -tubulin partial sequence data provided support for species concepts based on morphological and physiological characteristics.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.1
• /
• pp.7-11
• /
• 2007

The study was conducted on 162 adult male Haemonchus contortus of sheep collected from Avikanagar, Jaipur and Bikaner regions to diagnose the benzimidazole (BZ) resistance in H. contortus. The BZ resistance is primarily linked with the mutation in ${\beta}$-tubulin isotype 1 gene which substitute phenylalanine (Phe) into tyrosine (Tyr) at the 200 codon of the gene. An allele specific polymerase chain reaction (AS-PCR) technique was used for diagnosis of BZ resistance in H. contortus. In AS-PCR, one reverse primer (TGG 312) was used in two separate reactions with each of 2 forward primers (resistant TGG 331 and susceptible CAW 106 primer) that differed only at 3' nucleotide position. Therefore, the amplified products from resistant and susceptible parasites were produced 267 and 266 bp, respectively. A total of 162 parasites were genotyped, of which 130 parasites found homozygous resistant 'rr', 22 heterozygous 'rS' and 10 homozygous susceptible 'SS' type. The prevalence of 'rr' individuals was higher in Jaipur (98%) followed by Avikanagar (93%) and Bikaner (50%) regions. Overall, the prevalence of BZ resistant allele (r) was higher (87%) as compared to 13% of BZ susceptible allele (S).

• Research in Plant Disease
• /
• v.19 no.1
• /
• pp.49-54
• /
• 2013

Sclerotinia white rot disease was observed on 5 and 6-year-old ginseng (Panax ginseng) roots in Hongchun, Cheorwon, and Yanggu, Gangwon Province, Korea from 2006 to 2010. Symptoms included a brownish watery soft rot of the roots, and black sclerotia were often found on the rotten roots. The causal agent of the disease was identified as Sclerotinia nivalis based on cultural characteristics and sequence analyses of the internal transcribed spacer region of rDNA and ${\beta}$-tubulin gene with 100% sequence similarity. Pathogenicity tests were performed on 2-year-old ginseng roots with mycelium plugs without wounds. A watery soft rot of the roots and black sclerotia were observed 10 days after inoculation. These symptoms were identical to those observed on naturally infected roots. The same fungus was re-isolated from the lesions induced by artificial inoculation. This is the first report of sclerotinia white rot caused by S. nivalis on P. ginseng in Korea.

• The Korean Journal of Mycology
• /
• v.46 no.4
• /
• pp.495-503
• /
• 2018

Oak mushroom is cultivated using logs and sawdust media as substrates. In this study, fungi were isolated during a monitoring of indoor air in the oak mushroom cultivation houses located in Cheongyang-gun of Chungnam, Geoje-gun of Gyeongnam, Gumi-si of Gyeongbuk, Jangheung-gun of Jeonnam and Yeoju-si of Gyeongggi-do. Identification of the fungi based on morphology and molecular analysis of the internal transcribed spacer region and 28S rDNA, translation elongation factor translation elongation factor 1 a gene, and ${\beta}-tubulin$ gene revealed that six fungi, Cenangium acuum, Neopestalotiopsis surinamensis, Metarhizium marquandii, Periconia macrospinosa, Trichoderma petersenii, and Trichoderma paratroviride that have not been recorded previously in Korea.