01603nas a2200193   4500008004100000022001400041245004900055210004900104300001400153490000800167520103100175653002401206100001901230700002601249700001901275700002301294700002101317856007101338       2010                        eng d  a1878-614600aOospores progenies from Phytophthora ramorum0 aOospores progenies from Phytophthora ramorum  a369 - 3780 v1143 a<p>Oospores of <em>Phytophthora ramorum</em> were produced from intraspecific pairings between a European A1 and European or American A2 strains. Their viability was evaluated through colouration with tetrazolium bromide. The distribution of oospores in the different classes of colouration was similar to that found in other <em>Phytophthora</em> species (homothallic and heterothallic): most of the oospores stained purple, which corresponds to spores in dormancy. In order to produce single-oospore cultures, a method was developed to separate oospores from mycelium and chlamydospores. Germination of oospores was observed in 110, 250, 350 and 500-d-old cultures at a low proportion. Microsatellite marker analyses on oospore progenies revealed that the oospores resulted from hybridisation. More than 50 oospore progenies were characterised in terms of mating type, aggressiveness on <em>Rhododendron</em> leaves, and growth rate on two different media. The results are discussed in the context of pest risk analysis.</p>10aSexual reproduction1 aXavier, Boutet1 aAnnelies, Vercauteren1 aKurt, Heungens1 aFréderic, Laurent1 aAnne, Chandelier  uhttp://www.sciencedirect.com/science/article/pii/S1878614610000383