• The Plant Pathology Journal
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• v.30 no.4
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• pp.331-342
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• 2014

Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.40-47
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• 2010

To investigate genetic relationships either interspecies or intraspecies of 14 Korean Phytophthora species, sequence analyses of nuclear DNA (ypt gene and rDNA-IGS region) and mitochondrial DNA (Cox gene, $\beta$-tubuline gene, and EF1A gene) were performed. All of 14 Korean Phytophthora species clearly clustered into foreign isolates of each species. These Korean isolates in Phytophthora species also showed no correlation between molecular classification and morphological classification like as in case of foreigners. P. palmivora KACC 40167 reported previously from genetic groups of Phytophthora species in Korea was not consistent with the classification system, and therefore was required re-examination for the genetic group analysis. Korean isolates of P. drechsleri KACC 40195 showed very close relationship with P. cryptogea KACC 40161 above 94% bootstrap value in P. cryptogea-P. drechsleri complex group. Identification of these isolates is still unclear, because P. cryptogea and P. drechsleri were not differentiated in this study. On the other hand, it was required to unify species for these two species, since P. parasitica and P. nicotianae were clustered into a group on the level of 99 to 100% sequence homology. Comparing to the sequences of foreigners, Korean isolates were newly divided to ten groups in the phylogenic system. These results could be prepared useful informations to understand genetic diversity of Phytophthora species in Korea.

• Mycobiology
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• v.51 no.5
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• pp.333-342
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• 2023

Phytophthora species, classified under Oomycota, cause significant damage to various crops and trees. The present study introduced Phytophthora species, P. nagaii and P. tentaculata, new to Korea, which pose notable risks to their respective host plants. Our research provided a comprehensive description of these species taking into account their cultural features, morphological characteristics, and molecular phylogenetic analysis using the internal transcribed spacer rDNA region and cytochrome c oxidase subunit mtDNA genes (cox1 and cox2) sequences. In addition, this study first evaluated the sensitivity of P. nagaii and P. tentaculata to five anti-oomycete fungicides, finding both species most responsive to picarbutrazox and P. tentaculata resistant to fluazinam. The data can guide targeted treatment strategies and offer insights into effective control methods. The findings expand our understanding of the diversity, distribution, and management of Phytophthora species in Korea.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.103-107
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• 2016

To establish a rapid and accurate detection of Phytophthora pinifolia, which is a quarantine pathogenic fungus in Korea, a species-specific primer was developed based on the ras-related protein (Ypt1) gene. Species-specific primer based on the DNA sequences of Ypt1 gene amplified 193 bp polymerase chain reaction (PCR) product for P. pinifolia. The primer pair yielded the predicted PCR product size exactly in testing with target pathogen DNAs, but not from the other 10 species of Phytophthora and 14 species of other phytopathogenic fungi. The primer pair also showed only the species-specific amplification curve on realtime PCR on target pathogen DNA. The detection sensitivity of real time PCR using species-specific primer pair was 10 to 100 times higher than conventional PCR, with 1 to $10pg/{\mu}L$.

• Research in Plant Disease
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• v.17 no.2
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• pp.169-176
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• 2011

Phytophthora katsurae is the fungus responsible for chestnut ink disease. The objectives of this study were to determine if a single-strand conformation polymorphism (SSCP) analysis of rDNA-ITS region, elongation factor 1 alpha gene and ${\beta}$-tubulin gene could be used for rapid identification and genetic diversity of P. katsurae, and to assess the potential use of the SSCP technique as a diagnostic tool for P. katsurae. Each regions amplified by PCR using primers designed to overlap the genus Phytophthora were characterized for the Phytophthora species. PCR products were denatured and electrophoresed for SSCP analysis. P. katsurae isolates showed an unique pattern in SSCP analysis and were easily distinguished from other Phytophthora species used as the control. This indicates that SSCP analysis is an useful technique for distinguishing Phytophthora species from genetically close relatives, and show that the SSCP analysis of each region is an efficient detection tool for P. katsurae. But PCR-SSCP analysis of single-gene may have difficulty in distinguishing P. katsurae from other Phytophthora species. Therefore, PCR-SSCP analysis of multi-genes can be useful for rapid and effective identification of P. katsurae.

• Journal of Microbiology
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• v.39 no.2
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• pp.126-132
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• 2001

For rapid and secure differentiation of P. infestans from other Phytophthora species, two fragments obtained from randomly amplified polymorphic DNA (RAPD) profiles were selected as markers. Also, primers for in polymerase chain reaction (PCR) to detect P. infestans specifically were developed by analyzing the sequences of ITSII regions in rDNA of Phytophthora species. The primers, PISP-1 and ITS3 amplified a single. Fragment 450 bp of about in P. infestans, but not in other fungal or bacterial isolates. Annealing temperatures and template DNA quantities were varied for the optimization of PCR conditions. From the result of the PCR detection study, species-specific primers were selected under annealing temperatures ranging from 55$^{\circ}C$ to 61$^{\circ}C$, and template DNA levels ranging from 10 pg to 100 ng.

• Research in Plant Disease
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• v.26 no.2
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• pp.109-115
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• 2020

A disease causing leaf blight and vine rot was recognized on kudzu plants (Pueraria lobata) in Korea since 1991. A species of Phytophthora has been repeatedly isolated from the infected leaves. Identification in species level of the Phytophthora sp. remained unsolved. An isolate, KACC 47616 originally collected from Manchon Park in Daegu, has been kept in our laboratory. In 2013, three new isolates, KACC 47617 and KACC 47618 from Yeongyang and KACC 47619 from Gunwi in Gyeongbuk province, were collected and examined to classify up to species level by characterizing morphology, response to temperature and phylogenetic relationship. On the basis of morphological characters such as the nature of hyphal swelling, sporangia and sex organs, absence of chlamydospore production, optimum temperature for mycelial growth, and internal transcribed spacer rDNA and cytochrome oxidase subunit 1 sequence analysis of the pathogen, the causal fungus of kudzu plant was identified as Phytophthora asiatica.

• Mycobiology
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• v.31 no.4
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• pp.235-247
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• 2003

In order to investigate biodiversity and establish identification system for Phytophthora spp. in Korea, a variety of band pattern was produced by using the URP(universal rice primer). The fingerprint patterns of Phytophthora spp. showed many common and variable fragments according to their isolates in distinct genotypes. In particular, P. drechsleri was classified into four distinct types(I to IV). P. drechsleri(KACC 40498 and KACC 40499) and P. cryptogea(KACC 40413) appeared to have almost equal bands despite their being different species. Ninety isolates of Phytophthora spp. were clustered into 13 groups based on UPGMA(unweighted pair group method with arithmetic means) analysis. These DNA fingerprinting data would be helpful for inter- and intra-species identification of Phytophthora species.

• The Plant Pathology Journal
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• v.15 no.4
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• pp.228-235
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• 1999

Genetic diversity of ninety-five Korean isolates of Phytophthora was investigated on the basis of PCR-RFLP of ribosomal DNA. The isolates were previously identified as following fifteen species by mycological and cultural characteristics; P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamoni, P. citricola, P. citrophthora, P. cryptogea, P. drechsleri, P. erythroseptica, P. infestans, P. megasperma, P. nicotianae, P. palmivora and P. sojae. The regions of small subunit (SSU) and internal transcribed spacer (ITS) of rDNA were amplified with primer pair, NS1 and ITS4, by polymerase chain reaction (PCR) and digested with nine restriction enzymes. P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamomi, P. citricola, P. citrphthora, P. infestans, P. nicotianae and P. palmivora showed specific band patterns for each species. However, P. sojae and P. erythroseptica presented identical band patterns and P. cryptogea, P. drechsleri and P. megasperma were divided into six groups, which were not compatible with delineation of the species. A group originated from cucurbits showed distinct band patterns from other groups, but the other five groups were closely related within 96.0% similarity, forming one complex group. Consequently, Korean isolates of Phytophthora were divided into thirteen genetic groups and each group was readily differentiated by comparing digestion patterns of AvaII, HaeIII, MboI, HhaI and MspI. Therefore, PCR-RFLP of rDNA using the five enzymes can be used to differentiate or identify the Phytophthora species reported in Korea so far.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.651-655
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• 2000

Polymerase chain reaction (PCR) was used to specifically detect Phytophthora infestans by analyzing the sequences of the ribosomal internal transcribed spacer regions (ITS) in the rDNA of the Phytophthora species. Based on the sequence data, PISP-1 together with the ITS3 primer were used to detect p. infestans. A single ca. 450 bp segment was observed in P. infestans, but not in the other fungal or bacterial isolates. Two factors, the annealing temperature and template DNA quantity, were investigated to determine the optimal conditions. Using these species-specific primers, a unique band was obtained within annealing temperatures of $55^{\circ}C$-$61^{\circ}C$ and template DNA levels of 10 pg-100 ng.