• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.215-218
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• 2002

To confirm the antifungal activity to plant pathogenic fungi, Rhizoctonia solani, Rhizoctonia solani AG2-2, Fusarium oxysporium, Phytophthora dreschler, Alternaria sp. were selected. Helicosporium has the antifungal activity to Rhizoctonia solani, Rhizoctonia solani AG2-2, while Fusarium oxysporium, Phytophthora dreschler did not affected even though Alternaria made a feeble response to that antifungal compounds. From $^1H-NMR$ spectrum of antifungal compound, this compound was guessed to be a structure corresponding to cholesterol.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.57-63
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• 2006

This study was carried out to investigate control efficacy of natural compound, TGR-N1 against turfgrass fungal diseases. TGR-N1 showed antimicrobial activity in vitro. Rhizoctonia solani AG 1-1, Rhizoctonia solani AG2-2, Rhizoctonia cerealis, Sclerotinia homoeocarpa and Colletotrichum graminicola were inhibited by 500 times and 1,000 times of diluents of TGR-N1. Pythium spp. was not inhibited by the same diluents of TGR-N1. The TGR-N1 also showed a remarkable antifungal activity against Rhizoctonia solani AG 1-1, Rhizoctonia solani AG2-2 in field. This study proved the antifungal activity of natural compound, TGR-N1 and showed its potential as a natural pesticide.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.314-318
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• 1994

Incidence of stem rot on carnation (Dianthus caryophyllus L.) ranged 11 to 29% in Namwon and Chongup area during the growing seasons from 1993 to 1994. Among 129 isolates from carnations in Namwon, 77 isolates were identified as Rhizoctonia solani, 38 isolates were Fusarium oxysporum and 14 isolates were not identified. Among 169 isolates in Chongup, 19 isolates were identified as R. solani, 106 isolates as F. oxysporum and 44 isolates were not identified. Among 77 isolates of R. solani isolated from the specimens of Namwon, 52 isolates were classified as anastomosis group AG 2-2 by anastomosis test, 14 isolates as AG 2-1 and 11 isolates as AG 4. Among 19 isolates from specimens of Chongup, 14 isolates were classified as anastomosis group AG 2-2 and 5 isolates as AG 4. Pathogenicity tests revealed that isolates of F. oxysporum and R.solani AG 2-2 were highly virulent and isolates of R.solani AG 2-1 and AG 4 were mildly virulent.

• Weed & Turfgrass Science
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• v.2 no.4
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• pp.387-394
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• 2013

The Rhizoctonia blight causing by Rhizoctonia spp. is an important disease of turfgrass, requiring fungicide application to maintain acceptable conditions for turfgrass good qualities in the golf course. The experiment was conducted to determine the mean 50% effective concentration inhibiting mycelial growth ($EC_{50}$) value of to flutolanil, pyraclostrobine and hexaconazole to Rhizoctonia solani AG-1 IB, Rhizoctonia cerealis and Rhizoctonia solani AG2-2IV isolated from Gyeongbuk province of Korea in vitro. Five discriminatory concentrations of each fungicide were used to detect in vitro sensitivity. The mean of $EC_{50}$ values to three systemic fungicides was the lowest isolate of R. solani AG-1 IB. However, the sensitivity of fungicides to Rhizoctonia solani AG2-2IV were higher mean $EC_{50}$ value of 0.026 ${\mu}g\;a.i.\;ml^{-1}$ of pyraclostrobine and 0.044 ${\mu}g\;a.i.\;ml^{-1}$ of flutolanil. R. cerealis was the lowest sensitivity to hexaconazole which was an average $EC_{50}$ value of 0.022 ${\mu}g\;a.i.\;ml^{-1}$. Inhibition of mycelial growth rate (%) by three combine fungicides using the $EC_{50}$ value of each fungicide was the highest R. solani AG2-2IV. Results of this study were may confirmed in vitro response fungicide of three Rhizoctonia species for control of Rhizoctonia blight in the field.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.266-270
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• 2012

Stem canker and tuber rot symptoms were observed on yam grown in Andong and Jinju, Korea in 2011. A total of 20 isolates of Rhizoctonia and allied fungi were obtained from the symptomatic plants. Among the isolates, 8 isolates were identified as Rhizoctonia solani and 12 isolates as Ceratobasidium sp. based on rDNA-internal transcribed spacer (ITS) sequence similarity. In the cluster analysis of rDNA-ITS sequences, 7 isolates of R. solani belonged to AG 2-2IIIB and remaining one to AG 1-1A. In addition, among the 12 isolates of Ceratobasidium sp., 7 isolates belonged to AG-Fa, three isolates to AG-A and the other two isolates to AG-Fb and AG-O, respectively. Pathogenicity tests showed that all the R. solani AG 2-2IIIB isolates are pathogenic on stem and tuber of yam but R. solani AG 1-1A and all the Ceratobasidium isolates are non-pathogenic. The results indicate that R. solani AG 2-2IIIB is an important pathogen causing stem canker and tuber rot on yams grown in the study areas. This is the first report of R. solani AG 2-2IIIB causing stem canker and tuber rot of yam in Korea.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.357-360
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• 2022

In July 2021, we surveyed diseases affecting wild vegetables grown in Hongcheon, Gangwon Province, Korea. During this survey, we observed severe seedling rot symptoms in Kamchatka goatsbeard (Aruncus dioicus) grown in a vinyl greenhouse. The incidence of the disease in the plant seedlings was 1-10%. Diseased seedlings from this population were collected, and fungi were isolated from leaf and petiole lesions. Rhizoctonia sp. was consistently isolated from the lesions. We examined the morphological and cultural characteristics and anastomosis groups of nine Rhizoctonia sp. isolates obtained from the lesions. The results revealed that all isolates corresponded to Rhizoctonia solani AG-1(IB). Three isolates of R. solani AG-1( IB) were evaluated to determine their pathogenicity towards Kamchatka goatsbeard seedlings through artificial inoculation. The tested isolates caused rot symptoms on the inoculated plant seedlings. The symptoms were similar to those observed in plant seedlings from the vinyl greenhouse. We found that R. solani AG-1(IB) caused seedling rot of Kamchatka goatsbeard.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.40-45
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• 2000

Rhizoctonia solani Kuhn[Thanatephorus cucumeris (Frank) Donk]is a destrutive soil-borne plant pathogen affecting many agricultural crops worldwide. R. solani is divided into anastomosis groups based on the ability of the hyphae to fuse, and into subgroups based on morphological, physiological characteristics. AG classifications are convenient and useful in identifying primary causal agents of Rhizoctonia diseases, although the mechanism of anastomosis is not fully understood. Beacause of the difficulties, we sought to develop a more direct method for genetic identification and charaterization of R. solani. Twenty nine isolates of R. solani were used for the analysis of genetic relationships among themselves and for rapid anastomosis grouping with AFLP method. All isolates studied were divided into five groups. Isolate 6 was included in AG-3 with 67% genetic similarity. When isolates 3 was compared with 13 and 10 each, they showed more than 84% and 83% similarity, respectively. Isolates 3, 4, 5, 13, and 16 were included in AG-1 with 83% genetic similarity. Isolates 1, 7, and 8 were included in AG-1(IB).

• Korean Journal Plant Pathology
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• v.10 no.1
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• pp.7-12
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• 1994

Incidence of radish disease caused by Rhizoctonia solani ranged from 1 to 30% in fields located at Hwaseong, Naju and Yeoncheon in Korea during the growing seasons in 1989, 1990 ad 1993. A total of 133 isolates of R. solani was obtained from the diseased seedlings, leaves and roots of radish collected. The fungus was most commonly isolated from the roots. Among 133 isolates of R. solani, 56 isolates were classified as anastomosis group AG-1 by anastomosis test, 37 isolates as AG-2-1, and 40 isolates as AG-4. Among the isolates of AG-1, 26 isolates were grouped as cultural type IA, and the others as cultural type IB. Cultural types IA and IB of AG-1, were isolated from the leaves, AG-2-1 from the roots, and AG-4 from the seedlings, leaves and roots. Pathogenicity tests revealed that the AG-1(IA) isolates were highly virulent on leaves of radish, but avirulent on the seedlings, petioles and roots. The AG-1(IB) isolates were highly virulent on the leaves, but mildly virulent on the seedlings and avirulent or mildly virulent on the petioles and roots. The AG-2-1, isolates were mildly virulent on the leaves and seedlings and mildly or highly virulent on the petioles and roots. The AG-4 isolates were highly virulent on the seedlings and mildly or highly virulent on the leaves, petioles and roots.

• Asian Journal of Turfgrass Science
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• v.12 no.3
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• pp.183-194
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• 1998

Of crude extracts from 30 species belonging to the 21 families of medical plants, the crude extracts from Cinnamomum cassia, Paeonia moutan, Dictamnus dasycarpus showed highly antifungal activities against Rhizoctonia solani AG1-1 and R. solani AG2-2. The antifungal activity of C. cassia and P. moutan against R. solani AG1-1 were the highest through 100% methanol extraction, but the one of D. dasycarpus were the highest through 80% methanol extraction. On the other hand, against R. solani AG2-2 the antifungal activity of them were the highest through 100% methanol. C. cassia P. mouton and D. dasycarpus showed over 60% inhibition of mycelial growth against R. solani AG1-1 and R. solani AG2-2 on up to 500 fold dilution. The crude extract of P. moutan showed broader antifungal spectrum compared with those of C. cassia and D. dasycarpus. The crude extract of C. cassia was not phytotoxic at over 250 fold dilution and the crude extract of P. moutan was not phytotoxic at over 100 fold dilution. The crude extract of D. dasycarpus was not phytotoxic even at full concentration. The control values of P. moutan and D. dasycarpus were increased 75.0% and 79.1% respectively 30 days after treatment.

• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.257-265
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• 1995

Morphological characteristics and pathogenicity of Rhizoctonia species causing blight diseases of turfgrasses were studied. The species were identified as Rhizoctonia cerealis Van der Hoeven, R. oryzae Ryker et Gooch, and R. solani $K{\ddot{u}hn}$ based on their morphological and cultural characteristics. Isolates of R. solani were assigned to anastomosis groups (AG) with cultural type 1 (1A), 2-2 (IIIB), and 2-2 (IV). R. cerealis, R. oryzae and R. solani induced sheath rot and foliar blight symptoms on creeping bentgrass (Agrostis palustris) and zoysiagrass (Zoysia japonica). Inoculation tests showed that disease severity with isolates of R. cerealis and R. oryzae were more serious to creeping bentgrass than zoysiagrass. AG 1(1A) isolates of R. solani were strongly pathogenic on creeping bentgrass, but moderate to zoysiagrass. AG 2-2 (III) isolates were moderately pathogenic to zoysiagrass, but weakly to creeping bentgrass. AG 2-2 (IV) isolates from zoysiagrass were moderately pathogenic to zoysiagrass, but weakly to creeping bentgrass.