02337nas a2200193   4500008004100000022001300041245006400054210006400118260001100182300001400193490000800207520172900215100001701944700002301961700001701984700002202001700002102023856009902044       2002                        eng d  a0953756200aThree new species of Phytophthora from European oak forests0 aThree new species of Phytophthora from European oak forests  c4/2002  a397 - 4110 v1063 a<p>In several studies of oak decline in Europe, one semi-papillate (<em>Phytophthora psychrophila</em> sp. nov.) and two nonpapillate homothallic <em>Phytophthora</em> species (<em>P. europaea</em> sp. nov. and <em>P. uliginosa</em> sp. nov.) were isolated, together with other <em>Phytophthora</em> species, from rhizosphere soil samples which could not be assigned to existing taxa. <em>P. psychrophila</em> differs from other semi-papillate species of Waterhouse's morphological Group IV, like <em>P. ilicis</em> and <em>P. hibernalis</em>, by its uniform, dome-shaped and cotton wool-like colony growth pattern on V8 juice agar and malt extract agar, the occurrence of sympodially branched primary hyphae, the high variation in size and shape of the sporangia, shorter pedicels, lower optimum temperature for growth, and internal transcribed spacer (ITS) sequences. <em>P. europaea</em> is distinguished from related nonpapillate Group V and VI species, namely <em>P. fragariae, P. cambivora</em>, and the 'alder phytophthora', by producing oogonia with tapered bases, irregular walls and exclusively paragynous antheridia, its cardinal temperatures for growth, and ITS sequences. <em>P. uliginosa</em> differs from related Group V and VI species by its large oogonia with exclusively paragynous antheridia, the predominant occurrence of ellipsoid sporangia with markedly wide exit pores, its slow growth, low cardinal temperatures, its colony growth patterns, and ITS sequences. <em>P. uliginosa</em> is separated from <em>P. europaea</em> by its larger oospores without tapering bases, lower cardinal temperatures and growth rates, different colony growth patterns, and greater aggressiveness on <em>Q. robur</em>.</p>1 aJung, Thomas1 aHansen, Everett, M1 aWinton, Lori1 aOßwald, Wolfgang1 aDelatour, Claude  uhttps://forestphytophthoras.org/references/three-new-species-phytophthora-european-oak-forests