• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.103-108
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• 1998

A Pythium species was isolated from roots of lisianthus (Eustoma grandiflorum) showing wilt symptoms and reduced growth in a greenhouse at Ichon, Kyonggi-do in 1997. The Pythium species was identified as Pythium spinosum Sawada based on various mycological characteristics. The isolate was strongly pathogenic when inoculated to root of lisianthus plants in pots. The diseased plants showed typical symptoms of root and crown rot, resulting in reduced growth of roots and shoots, and consequently wilting of the above ground part of plants.

• Research in Plant Disease
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• v.22 no.3
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• pp.190-193
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• 2016

In 2010 and 2012, damping-off symptoms were found on melon seedlings grown in Yeongam and Suncheon, Korea. Water-soaked and discolored lesions appeared on the lower stems of the infected plants. The diseased plants became wilted and stunted, and eventually collapsed. On the basis of morphological characteristics and molecular analyses of internal transcribed spacer (ITS) rDNA and cytochrome oxidase II (cox2) sequences, the causal organism was identified as Pythium spinosum. The isolates were pathogenic to melon under pot conditions. To our knowledge, this is the first report of P. spinosum causing damping-off on melon in Korea.

• The Korean Journal of Mycology
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• v.21 no.4
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• pp.293-300
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• 1993

For the enzymes AAT, GmDH, ME, GPI, LDH and IDH, nine, seven, four, nine, seven, and four different phenotypes, respectively, were observed. All six isolates of an unidentified sterile Pythium sp. isolated from field soil showed the same band positions for all six enzymes compared. These phenotypes were not similar to any of the known Pythium species. Two isolates of unknown Pythium species (145 and 299) showed the same band positions for all six enzymes. The phenotypes for all three unknown Pythium spp. were different from the other species in the experiment. Five isolates of P. heterothallicum showed the same band positions for all enzymes compared except one enzyme, lDH. Two isolates of P. torulosum showed the same band petitions for enzymes AAT, GmDH and ME, and three isolates of P. totulosum showed the same positions for enzymes GPI, LDH, and IDH. Single isolates of P. spinosum and P. irregulare showed the same band positions for enzymes AAT, GmDH and GPI. In conclusion, sterile types of Pythium species showed 100% similarities among themselves but did not show any similarity with all isolates of P. heterothallicum and P. spinosum isolate, and showed very low similarities with other isolates in general except with unknown Pythium isolate 306. Similarity levels between different species were low in general with few exceptions.

• The Korean Journal of Mycology
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• v.3 no.2
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• pp.7-12
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• 1975

Three species of Pythium previously not recorded in Korea were found during 1975. Pythium spinosum Sawada was isolated from diseased cabbage seedlings, P. myriotylum Dreschl. was isolated from kidney bean and P. butleri Subramanium from cucumber, spinach, red bean and radish. Pathogenicity of isolates of P. butleri and P. myriotylum was confirmed in pathogenicity tests but P. spinosum appeared to be non-pathogenic. Several isolates failed to sporulate satisfactorily on cornmeal agar and some produced degenerate oogonia after sub-culturing on this medium. Sunflower seed agar was found to be a suitable alternative medium. The validity of previous records of P. debaryanum Hess in Korea is discussed.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.402-406
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• 1996

Pythium 5종, 16균주를 공시하여 담수직파한 벼에 대한 병원성을 CMA 배지와 growth chamber 검정법에 의하여 검정한 결과 P. arrhenomanes 1398 균주가 가장 강한 병원성을 보였으며, 다음은 균주에 따라 차이가 있었으나 P. irregulare와 P. spinosum도 병원성이 강하였으며, P. dissotocum과 P. catenulatum의 균주는 병원성이 약하거나 없엇다. CMA 배지 검정때 P. arrhenomanes 1398 균주의 병원성은 주.dirks 2$0^{\circ}C$ 또는 3$0^{\circ}C$의 항온처리보다 주간 3$0^{\circ}C$, dirks 2$0^{\circ}C$의 변온 처리에서 높았다. Growth chamber 검정법으로 병원성을 검정할 때에는 벼알접종원을 이용하는 것이 효과적이었다.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.484-490
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• 1998

Microorganisms associated with seed-rhizome rot of gingers preserved in three underground storage caves were identified with respect to rot types. Rot patterns were grouped into 4 different types : yellow soft rot, brown rot, localized ring rot, and water-soaked rot. Water-soaked rot was highest in frequency with 40% and ring rot the least with 14%. Causal pathogens differed with rot type, yellow soft rot by Erwinia carotovora and Pseudomonas aeruginosa, brown rot by Fusarium solani and Pseudomonas aeruginosa, localized ring rot by F. solani, and water-soaked rot by Pythium spinosum and P. ultimum. Pythium myriotylum, the causal pathogen of ginger rhizome rot which occurs severely in fields was rarely detected from storage seed-rhizomes suggesting its minor involvement with storage rot. Pathogenic Pythium isolates were frequently obtained from both rhizome surface and inner tissues of rotten rhizomes. Detection frequency of Pythium isolates in inner tissues decreased as increasing distance from rhizome surface. In wound-inoculation tests, above pathogens caused a varying degree of rot on healthy rhizomes at 15$^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$ with increasing severity at higher temperatures.