02233nas a2200229 4500008004100000022001400041245007500055210006900130260002600199300001400225490000800239520155400247653001001801653001301811653002201824653003801846653002001884100001501904700001501919700001401934856005501948 2006 eng d a1439-043400aPCR-based DNA Markers for identifying hybrids within Phytophthora alni0 aPCRbased DNA Markers for identifying hybrids within Phytophthora bBlackwell Verlag GmbH a168–1770 v1543 a

Two pairs of oligonucleotide primers were designed for the polymerase chain reaction (PCR)-based detection and differential identification of naturally occurring interspecific hybrid types (subspecies) of Phytophthora alni, all of which cause collar rot of alder trees. Primer pairs were derived from randomly amplified polymorphic DNA (RAPD) fragments that were unique to various subspecies of this alder pathogen. The primer pair set, SAP1/SAP2 (SAP), was derived from a 0.93-kb RAPD fragment amplified from P. alni ssp. alni. The primer pair set, SWAP1/SWAP2 (SWAP), was derived from a 1.13-kb fragment amplified from P. alni ssp. uniformis. Patterns of SAP and SWAP amplification enabled distinction among the three subspecies. No PCR products were amplified from isolates of 31 other Phytophthora spp. examined, including P. cambivora and P. fragariae, the suspected progenitors of P. alni. The SAP and SWAP primer sets were able to detect a minimum of 10 pg of DNA from pure cultures or DNA extracted from as few as 10 zoospores. Pathogen DNA could also be amplified directly from bark lesions of artificially inoculated and naturally infected common alders and from lesions developed on common cherry-laurel leaves used in baiting the pathogen from infested soil. Direct detection of pathogen DNA from alder tissue using SAP and SWAP primer sets should prove useful in developing measures for effective quarantine and management of P. alni.

10aAlnus10aoomycete10aPhytophthora alni10apolymerase chain reaction markers10aspecies hybrids1 aBakonyi, J1 aNagy, Z Á1 aÉrsek, T uhttp://dx.doi.org/10.1111/j.1439-0434.2006.01079.x