02379nas a2200241   4500008004100000245011500041210006900156260003800225300001200263490000700275520158700282653002801869653002501897653002501922653002601947653001401973100001801987700001702005700002002022700001902042700001902061856005702080       2009                        eng d00aIsolation, identification and characterization of Phytophthora katsurae, causing chestnut ink disease in Korea0 aIsolation identification and characterization of Phytophthora ka  bKorean Society of Plant Pathology  a121-1270 v253 a<p>Since July 2005, survey of chestnut ink disease was carried out in chestnut stands located at southern parts of Korea. Dead chestnut trees showing inky ooze on necrotic trunks were found in two different locations. In order to isolate and identify the causal fungus, infected tissues and soil samples around dead or dying trees were collected and placed on <em>Phytophthora</em>-selective medium. Rhododendron and chestnut tree leaves were used as a bait to isolate the fungus from soil samples by attracting zoospores in soil suspensions. On V-8 culture medium, the isolates produced homothallic oogonia with protuberances (34.0-46.2×21.9-26.7㎛) abundantly, but did not produced sporangia. Mass production of sporangia was possible by immersing agar plugs with actively growing mycelium in the creek water at 18oC for 3 days. Sporangia were papillate, and ovoid to obpyriform (17.0-38.9×14.6-29.2㎛) in shape. Comparison of the ITS sequences revealed that the isolates had 100% identity to the <em>P. katsurae</em> isolates from Japan and New Zealand and 99.6% identity to other <em>P. katsurae</em> isolates. All of the examined isolates from Korea were completely identical to each other in ITS sequence. Numerous sporangia were formed in filtered as well as unfiltered creek water, but no sporangia formed in sterilized distilled water. Light induced sporangia formation, but has no influence on oospore formation. Amendments of β-sitosterol in culture media have no significant effect on mycelial growth but significantly stimulate oospore and sporangia formation.</p>10aamphigynous antheridium10achestnut ink disease10ahomothallic oogonium10aPhytophthora katsurae10asporangia1 aLee, Jong Kyu1 aJo, Jong Won1 aShin, Keum Chul1 aLee, Sang Hyun1 aLee, Sang Yong  uhttp://www.dbpia.co.kr/view/ar_view.asp?arid=1207770