• The Plant Pathology Journal
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• 제20권1호
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• pp.58-62
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• 2004

White root rot of wild white clover (Trifoliorum repens) caused by isolate BWC98-105 has been first reported in Korea. Typical symptoms on root include water-soaked and dark-brown rot, resulting in complete blight of the whole plant. The fungus grew well at $20-28^{\circ}C$ and produced abundant sclerotia at 10-15 days after full mycelial growth on potato dextrose agar. Sclerotia were brown to dark-brown in color and 1-3 mm in length. When white clover plants were inoculated with mycelial suspension ($10^5$ cfu/ml) of isolate BWC98-105, the plant shoots were killed within 4-6 days and the roots were completely blighted. Sclerotia were also formed on the surface of the root covered with whitish mycelia within 10-15 days in the field. All nine isolates developed high incidences of white root rot disease on white clover seedlings, of which the symptoms were similar to those observed in the fields. Hence, their pathogenicity was confirmed on white clover. The infection rate of the fungal isolates varied from 78.5% to 95.2%, among which BWC98-105 was the most virulent isolate. The weeding efficacy of the fungus was maintained until the following year, leading to a significant reduction of reshooting. The fungus was specifically parasitic to white clover, but not to four lawn species including zoysiagrass (Zoysia japonica) under greenhouse test. The fungus also had no response to some Gramineae species including rice, but caused little damage to five species of Leguminosae.

• Mycobiology
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• 제44권2호
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• pp.85-92
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• 2016

Mycoherbicides are exclusive biotechnology products which offer a non-chemical solution to control noxious weeds on the land as well as aquatic in systems, viz a viz saving environment from hazardous impact of synthetic chemicals. The present paper highlights the mycobiota associated with Eichhornia crassipes infesting Harike wetland area of Punjab and evaluation of their pathogenic potential for futuristic application as a mycoherbicide. Of the 20 isolates tested by leaf detached assay and whole plant bioassays, only one isolate (#8 BJSSL) caused 100% damage to E. crassipes. Further, the culture filtrate of this isolate also exhibited a similar damage to the leaves in an in vitro detached leaf assay. The potential isolate was identified as Phaeoacremonium italicum using classical and modern molecular methods. This is the first report of P. italicum as a pathogen of E. crassipes and of its potential use as a biological control agent for the management of water hyacinth.

• The Plant Pathology Journal
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• 제19권2호
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• pp.92-96
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• 2003

The study was conducted to determine the cultural conditions and the effect of inert fillers for melanization and sporulation abilities of sodium alginate pellets, and the weeding efficacy of the formula in the field. Melanin production of E. nematosporus was affected by striking frequency. Percentage of melanized beads was increased to 80.6% at higher rpm up to 180. The melanized pellets produced more conidia with abundant mucilage than unmelanized pellets. Shaker culture of Epicoccosorus nematosporus with sodium alginate yielded a total of 55 mg per 100 pellets. Percentage of melanized pellets was highest with 81.0% and 83.3% of melanization, when wheat bran and rice polish were amended and produced the conidia with 65.4 and 68.4 mg per 100 pellets, respectively. When 1 L of conidial suspension of 6.0$\times$$10^5$ conidia per ml was applied on 30-day-old plants in a plot, 74.5% of the plants were killed within 20 days, whereas, its melanized sodium alginate pellets killed 57.8% of the plants in the same period. The number of tuber formation of Eleocharis kuroguwai in the untreated control plots was 128.5 per plot, but those of the plots treated with conidial suspension and melanized pellets were 22.1 and 39.7, respectively, at the end of the season. Results of this study showed that melanization of mycelia-mixed sodium alginate are an important sporulation factor in E. namatosporus as a mycoherbicide.

• 한국식물병리학회지
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• 제14권6호
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• pp.578-582
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• 1998

In greenhouse studies, control efficacy of water chestnut (Eleocharis Kuroguwai) by Epicoccosorus nematosporus was affected by temperature and dew condition. The appressoria were formed abundantly in the range of 20~28$^{\circ}C$. When stem segments o(30 cm long) of the water chestnut were inoculated with the conidial suspension of E. nematorporus, the mean conidial number attacted amounted to 2,545 conidia. Out of 2545 conidia attacted to the stem pieces, 1,733 (68%) conidia formed appressoria. When these stem pieces were treated for 24 hr at 28$^{\circ}C$ under dew condition, 183,1 (7.2%) lesions were formed 10 days after incubation. The time necessary for the death of the plants was about 24 days. Appressoria were formed at 15~35$^{\circ}C$, but decreased rapidly in their numbers at the temperature lower than 1$0^{\circ}C$ or at 35$^{\circ}C$. The appressoria formation seemed to be depended on the dew duration, which was effective to the lesion formation and plant mortality. Under dew duration of 16~24 hr with temperature range of $25^{\circ}C$ to 3$0^{\circ}C$, the weed control was increased up to 93.9%. There were no differences between the first and second or third dew treatments. A delay of 2 or 3 days in dew treatment did not increase the mortality of plants. For the use of E. nematosporus as a mycoherbicide of water chestnut, a conidial suspension should be applied when dew conditions are kept for 12 hr after inoculation.

• 농약과학회지
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• 제5권4호
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• pp.33-39
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• 2001

물달개비에 병을 일으키는 Pythium myriotylum 균주를 2000년 충청남도 유성 지역에서 수집한 시료로부터 분리하였으며, 실험실과 온실에서 생물학적 방제제로서의 가능성을 조사하였다. 이 곰팡이는 넓은 온도 범위에서 잘 자랐으며 특히 생장적온은 $35^{\circ}C$ 이었다. 또한 $30{\sim}35^{\circ}C$에서 물달개비에 강한 병원성을 나타냈다. 여뀌바늘, 알방동사니, 사마귀풀, 올챙이고랭이 등의 논잡초에는 병원성이 강하였으나, 강피에는 병을 일으키지 못하였다. 벼에 대한 생육시기별 및 품종에 따른 병 발생을 조사한 결과, 발아 직후의 벼는 생육에 저해를 받았으나 1엽기 이상의 벼는 영향을 받지 않았다. 또한 12 품종의 $3{\sim}4$엽기 벼도 MD2에 의하여 영향을 받지 않았다. 그리고 배추, 옥수수, 콩 등 12종의 작물에 대한 병원성 실험을 실시하였는데, 밀을 제외한 11종의 작물은 영향이 없었다. 이상의 결과로부터 Pythium myriotylum MD2는 1엽기 이상의 벼에 대하여 선택성이 있으며, 물달개비뿐만 아니라 여러 종류의 일년생 논잡초에 대하여 강한 병원성을 보이고 또한 작물에 대한 영향도 적어서 생물적 방제제로서 가능하리라 생각되었다.