02050nas a2200169   4500008004100000022001400041245009600055210006900151260001200220300001400232490000700246520153600253100001401789700001301803700001401816856005001830       2002                        eng d  a0191-291700aFirst report of bleeding canker caused by Phytophthora cactorum on horse chestnut in Turkey0 aFirst report of bleeding canker caused by Phytophthora cactorum   c06/2002  a697 - 6970 v863 a<p>Bleeding canker on horse chestnut (<em>Aesculus</em> sp.), caused by <em>Phytophthora cactorum</em> (Lebert and Cohn) Schröeter previously has been reported from the United States and Europe (1). In August 2000, it was found for the first time in a park in Ankara Province, Turkey. Symptoms included sparse yellowish brown foliage with abnormally small leaves, and dark-stained spots or dark brown necrosis of the bark on the trunk and main branches, with or without a reddish black gummy exudate. <em>P. cactorum</em> was isolated from tissues taken from the margins of necrotic bark. Pure cultures were slightly radiate, fluffy but not dense, and had short aerial hyphae when grown on carrot agar, potato dextrose agar, or V8 agar. Sporangia were ovoid, strongly papillate, and averaged 35.6 μm in length and 26.8 μm in width (range: 24 to 55 μm × 19 to 40 μm). The isolates were homothallic with smooth-walled paragynous oogonia ranging from 23.5 to 34.5 μm in diameter. To satisfy Koch's postulates, mycelium of <em>P. cactorum</em> was placed under the bark of six branches of healthy horse chestnut. Noninoculated wounds served as controls. Four months later a reddish black gummy exudate was observed oozing from the inoculated wounds, and the bark tissue was necrotic for 3 to 4 cm around each infection. <em>P. cactorum</em> was successfully reisolated from the necrotic bark tissue. Control wounds remained healthy. To our knowledge, this is the first report of this disease on horse chestnut in Asia Minor.</p>1 aIntini, M1 aGurer, M1 aOzturk, S  uhttp://dx.doi.org/10.1094/PDIS.2002.86.6.697C