01806nas a2200181   4500008004100000022001400041245012800055210007100183260002500254300001200279490000800291520120300299100001701502700001901519700002101538700001701559856004801576       2005                        eng d  a0929-187300aSCAR–based PCR primers to detect the hybrid pathogen Phytophthora alni and its subspecies causing alder disease in Europe0 aSCAR–based PCR primers to detect the hybrid pathogen Phytophthor  bSpringer Netherlands  a323-3350 v1123 a<p>Since the 1990s, a new <em>Phytophthora</em> species hybrid has been jeopardizing the natural population of alders throughout Europe. This new <em>Phytophthora, P. alni</em>, has been suggested as a natural hybrid between two closely related species of <em>Phytophthora</em>. Little is known about the epidemiology of this pathogen, because its direct isolation is not always satisfactory. In this study we developed three pairs of Polymerase Chain Reaction (PCR) primers derived from Sequence Characterized Amplified Regions (SCAR) that allow discrimination among the three subspecies of <em>P. alni: P. alni subsp. alni, P. alni subsp. uniformis</em> and <em>P. alni subsp. multiformis</em>. These molecular tools were successfully used to detect <em>P. alni</em> directly in different substrates such as infested river water and soil, and necrotic alder bark, without the need for any prior baiting or isolation stages. An Internal Amplification Control (IAC) was included to help discriminate against false negative samples due to the potential presence of inhibitory compounds in DNA extracts. These molecular tools should be useful for epidemiological studies on this emerging disease.</p>1 aIoos, Renaud1 aHusson, Claude1 aAndrieux, Axelle1 aFrey, Pascal  uhttp://dx.doi.org/10.1007/s10658-005-6233-2