• Mycobiology
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• v.44 no.4
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• pp.335-337
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• 2016

During the growing season of 2015, leaf specimens with yellow rust spots were collected from Salix koreensis Andersson, known as Korean willow, in riverine areas in Cheonan, Korea. The fungus on S. koreensis was identified as the rust species, Melampsora yezoensis, based on the morphology of urediniospores observed by light and scanning electron microscopy, and the molecular properties of the internal transcribed spacer rDNA region. Pathogenicity tests confirmed that the urediniospores are the causal agent of the rust symptoms on the leaves and young stems of S. koreensis. Here, we report a new rust disease of S. koreensis caused by the rust fungus, M. yezoensis, a previously unrecorded rust pathogen in Korea.

• The Korean Journal of Mycology
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• v.33 no.2
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• pp.95-97
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• 2005

A rust disease occurred on Veratrum patulum in Deogyusan National Park, Jeollabukdo. The typical symptoms of the disease appeared as small, yellowish spots on leaves at first. The spots then turned brown, their edges rised slightly, and powdery mass of yellow or yellowish brown spores appeared on the lesions. Severely infected leaves blighted and eventually defoliated. Urediniospores were yellowish brown in color, globose, subglobose or ellipsoid in shape and $19{\sim}27\;{\times}\;17{\sim}24\;{\mu}m$ in size. Teliospores were brown in color, ellipsoid, ovate or oblong in shape and $19{\sim}36\;{\times}\;15{\sim}21\;{\mu}m$ in size, the apex mostly rounded, with hyaline or subhyaline conical papilla, the base rounded or attenuated, smooth. Pedicels hyaline or subhyaline, up to $38\;{\mu}m$ long. The causal fungus was identified as Uromyces veratri Schroeter based on mycological characteristics and host specificity.

• Mycobiology
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• v.42 no.1
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• pp.79-81
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• 2014

From June to October 2012, severe outbreaks of rust disease on Solidago virgaurea var. gigantea were observed in 5 different regions of Ulleung-do, Korea. Typical rust symptoms appeared as yellow spots, uredinia on leaves, and massive urediniospores covering the entire plant. Severely infected plants became discolored and died. On the basis of its morphological and molecular characteristics, the causal agent was identified as Coleosporium asterum. This pathogen has been reported as rust disease on S. virgaurea in the Canada and United States. In Korea, rust disease on S. virgaurea var. gigantea was reported as Uromyces rudbeckia in 1992. To the best of our knowledge, C. asterum is a novel rust pathogen on S. virgaurea var. gigantea in Korea.

• Research in Plant Disease
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• v.9 no.3
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• pp.125-127
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• 2003

Rust disease was occurred on Iris in several farmer's fields fields located in Hoehwa-myon, Goseong-gun, Gyeong-nam province in Korea. The typical symptoms of the disease appeared first as small, yellowish spot on leaves. The spots then turn brown, their edges rised slightly, and powdery mass of yellowish brown spores revealed on the lesions. Severely infected leaves were blighted and eventually died. Urediniospores were yellowish brown to reddish brown in color, obobid to obovoid in shape and 22~30 ${\times}$ 21~25${\mu}m$m in size. Teliospores were chestnet-brown in color, oblong or clavate in shape and 32~54 ${\times}$ 12~22${\mu}m$ in size. The causal fungus was identified as Puccinia iridis, based on morphological characteristics. This is the first report on the rust of Iris nertschinskia by Puccinia iridis in Korea.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.54-56
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• 2004

Rust disease was occurred on blackberry lily (Belamcanda chinensis) in several farmer's fields located in Heohwa-myon, Goseong-gun, Gyeongnam province in Korea. The typical symptoms of the disease appeared as small, yellowish spot on leaves at first. The spots then turned brown, their edges rised slightly, and powdery mass of yellow or yellowish green spores appeared on the lesions. Severely infected leaves were blighted and eventually died. Urediniospores were yellow or yellowish brown in color, globoid to ovoid in shape and $21{\sim}46{\times}18{\sim}38\;{\mu}m$ in size. Teliospores were brown in color, oblong or clavate in shape and $32{\sim}64{\times}12{\sim}26\;{\mu}m$ in size. The causal fungus was identified as Puccinia belamcandae based on morphological characteristics and host specificity. This is the first report on the rust of B. chinensis caused by P. belamcandae in Korea.

• Research in Plant Disease
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• v.13 no.3
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• pp.220-222
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• 2007

Rust disease on Korean Azalea (Rododendron yedoense) was occurred in Jeonju, Jeonbuk province of Korea. The typical symtoms of the disease appeared first as small yellowish spots on leaves. Uredinia were observed at hypophyllous of the leaves, yellow or dark yellow in color and globoid in shape with the size of $0.27{\sim}0.46{\times}0.31{\sim}0.61$ mm. Urediniospores were also observed in the leaves, yellow in color with globoid or ovoid in shape with the size of $17.1{\sim}29.2{\times}12.8{\sim}18.2{\mu}m$. Surface characterization of the spores revealed that these spores have papilla-like projections, which were made of $2{\sim}3$ annulation (SA; small annulate). Based on these morphological characterizations the causative fungus was identified as Chrysomyxa rhododendri.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.453-458
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• 2011

BACKGROUND: Coleosporium plectranthi, an obligate parasite, which is responsible for the rust disease of Perilla frutescens, a plant in Korea, commonly known as Perilla. All rusts are obligate parasites, meaning that they require a living host to complete their life cycle. They generally do not kill the host plant but can severely reduce growth and yield. Food and feed spoilage fungi cause great economic losses worldwide. It is estimated that between 5 and 10% of the world food production is wasted due to fungal deterioration. Rust disease of Perilla is highly frequent and is widely spread in Korea. The present study was designed to investigate a novel media for the urediniospore germination in vitro and anti-rust activity as well as GC-MS analysis of oak pyroligneous liquor. METHOD AND RESULTS: Urediniospores were collected from the infected leaf of Perilla. Spore suspension was made and the suspension was inoculated in the 2% water agar media with proper humidity, then they were incubated at $26^{\circ}C$ for 56 hrs. The GC-MS analysis of the oak pyroligneous liquor was also done to check the chemical composition. GC-MS analysis of the wood vinegar was found 15 compounds, among them o-mthoxyphenol (25.93%), 2,6-dimethoxyphenol (16.06%), 4-methylenecyclohexanone (10.69%), 2,3-dihydroxytoluene (7.84%), levoglucosane (6.14%) and propanoic acid (5.32%) were the major components. Different concentration of the oak pyroligneous liquor was used, and spore inhibition was recorded on the basis of spore counting. The best results were noted at the concentration of 50% solution where 31.8% spores were inhibited. CONCLUSION: On the basis of the chemical composition of the oak pyroligneous liquor and the activity recorded we can use it as an anti-rust agent.

• The Plant Pathology Journal
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• v.23 no.1
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• pp.7-12
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• 2007

Perilla rust is a damaging disease in perilla cultivation in Korea. Its causal agent was identified as Coleosporium plectranthi based on descriptions of morphological characteristics of spores and spore-producing fruiting structures(in uredinial and telial stages from perilla and in aecial stage from the alternate host pine) collected in 15 locations in Korea during the disease survey from 2004 to 2006. These characteristics were yellow or orange uredinium; globose or ellipsoid urediniospore of $20.8{\mu}m{\times}18{\mu}m$ in size; verruca of $0.3mm{\times}1.2mm$; orange telium; one-celled, oblong ellipsoid teliospore of $63.1{\mu}m{\times}19.7{\mu}m$ with one-layered crusts or four-celled(when mature), internal basidium of $64.2{\mu}m{\times}19.7{\mu}m$; ellipsoid to globoid basidiospore of $20.3{\mu}m{\times}12{\mu}m$; type 2 spermogonium; yellow, broadly ellipsoid peridial cell of $35.6{\mu}m{\times}23.1{\mu}m$; and broadly ellipsoidal or subglobose aeciospore of $25.9{\mu}m{\times}18.8{\mu}m$. Phylogenetic analysis of 28S rDNA sequences revealed the closest relatedness to those of the genus Coleosporium, a monophyletic group distinguished from other rust fungi and divided into two main lineages, one of which was C. plectranthi grouped with high bootstrap value(96%). In pathogenicity test, both aeciospores and urediniospores caused rust development on perilla leaves. This is the first description of C. plectranthi causing perilla rust with the first findings of its telial stage on perilla and the first rust disease on the aecial host in Pinus densiflora. These aspects would provide basic information for the development of control measures of the disease.

• Research in Plant Disease
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• v.26 no.3
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• pp.179-182
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• 2020

In July 2018, a serious rust symptom was found throughout the fringe trees planted in Gangjin-gun, Korea. Yellow and brown spots were observed on the adaxial (topside) surface of the collected fringe tree leaves, and yellow color aecia were observed on the abaxial (underside) surface leaves. The size of aeciospore and urediniospores of JCK-KCFR1 strain were measured to 41.2 ㎛ (Φ) and 28.84 ㎛ (Φ) with a light microscope. Phylogenetic analysis of the small subunit rRNA, internal transcribed spacer, and large subunit rRNA region indicated that JCK-KCFR1 strain is novel species of the genus Puccinia and closely related to Puccinia kusanoi, which has been reported a rust pathogen on bamboo. In May 2019, rust symptoms were also discovered on the bamboo leaves planted around the fringe tree on Muwisa-ro, and their telia and teliospores were observed on the abaxial leaf surfaces of the bamboo with 100% sequence homology with the rust of the fringe tree. This is the first report that Puccinia sp. JCK-KCFR1 is a new species that requires both primary (fringe tree) and alternative (bamboo) host plants to complete its life cycle in Korea.

• Research in Plant Disease
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• v.21 no.4
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• pp.337-340
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• 2015

During July to November 2014, severe rust infection was consistently found on Peucedanum japonicum growing farm in Yeosu, Korea. The rust was observed mainly on lower leaf surfaces. Symptoms of typical plants included yellow-orange rust pustules were observed on the petiole and leaf surface with small yellowish to chlorotic lesions on the upper surface. No symptom was observed on flowers. Uredinia were occurred amphigenous on leaf surface, and occasionally caulicolous, scattered or loosely aggregate, rounded to oblong, 0.4 to 4 mm in diameter, covered by epidermis, then naked, surrounded by ruptured epidermis, pulverulent, and brown. Urediniospores were ovate-ellipsoid, ellipsoid or subglobose, light brown, 20 to $45{\times}15$ to $35{\mu}m$, walls 2 to $4{\mu}m$ thick. The resulting sequences were deposited in GenBank with accession No. KT778808, KT778809, and KT778810, respectively. Since this was the first accession of 28S sequence Puccinia jogashimensis, there was no exact match in GenBank nucleotide database. On the basis of the morphological characteristics and phylogenetic analyses of 28S rDNA, the fungus was identified as P. jogashimensis. To our knowledge, this is the first confirmed report on the occurrence of P. jogashimensis on P. japonicum in Korea.