01377nas a2200217 4500008004100000022001400041245014600055210006900201260002900270300001400299490000600313520066300319653001500982653001300997653001501010100001701025700002401042700002101066700001701087856005501104 2007 eng d a1471-828600aCharacterization of microsatellite markers in the interspecific hybrid Phytophthora alni ssp. alni, and cross-amplification with related taxa0 aCharacterization of microsatellite markers in the interspecific  bBlackwell Publishing Ltd a133–1370 v73 a

Phytophthora alni ssp. alni is an interspecific hybrid oomycete causing a large-scale decay of alders throughout Europe. In this study we developed a set of 10 microsatellite markers that shows promise for population studies and for studying hybridization events between the parental species of the hybrid. Moreover, the genotype and the ploidy of the different subspecies of P. alni might be inferred from the quantitative ratio of amplified genome-specific alleles. Nine primer pairs cross amplified with the related species Phytophthora cambivora and Phytophthora fragariae and yielded distinct alleles.

10agenotyping10aoomycete10apolyploidy1 aIoos, Renaud1 aBarrés, Beno{\^ıt1 aAndrieux, Axelle1 aFrey, Pascal uhttp://dx.doi.org/10.1111/j.1471-8286.2006.01554.x01806nas 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

Since the 1990s, a new Phytophthora species hybrid has been jeopardizing the natural population of alders throughout Europe. This new Phytophthora, P. alni, has been suggested as a natural hybrid between two closely related species of Phytophthora. 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 P. alni: P. alni subsp. alni, P. alni subsp. uniformis and P. alni subsp. multiformis. These molecular tools were successfully used to detect P. alni 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.

1 aIoos, Renaud1 aHusson, Claude1 aAndrieux, Axelle1 aFrey, Pascal uhttp://dx.doi.org/10.1007/s10658-005-6233-202032nas a2200169 4500008004100000245010500041210006900146300001400215490000700229520147100236100001701707700002401724700002501748700002101773700001701794856005101811 2007 eng d00aDistribution and expression of elicitin genes in the interspecific hybrid oomycete Phytophthora alni0 aDistribution and expression of elicitin genes in the interspecif a5587-55970 v733 a

Phytophthora alni subsp. alni, P. alni subsp. multiformis, and P. alni subsp. uniformis are responsible for alder disease in Europe. Class I and II elicitin gene patterns of P. alni subsp. alni, P. alni subsp. multiformis, P. alni subsp. uniformis, and the phylogenetically close species P. cambivora and P. fragariae were studied through mRNA sequencing and 3' untranslated region (3'UTR)-specific PCRs and sequencing. The occurrence of multiple 3'UTR sequences in association with identical elicitin-encoding sequences in P. alni subsp. alni indicated duplication/recombination events. The mRNA pattern displayed by P. alni subsp. alni demonstrated that elicitin genes from all the parental genomes are actually expressed in this allopolyploid taxon. The complementary elicitin patterns resolved confirmed the possible involvement of P. alni subsp. multiformis and P. alni subsp. uniformis in the genesis of the hybrid species P. alni subsp. alni. The occurrence of multiple and common elicitin gene sequences throughout P. cambivora, P. fragariae, and P. alni sensu lato, not observed in other Phytophthora species, suggests that duplication of these genes occurred before the radiation of these species.

1 aIoos, Renaud1 aPanabières, Franck1 aIndustri, Beno{\^ıt1 aAndrieux, Axelle1 aFrey, Pascal uhttp://aem.asm.org/content/73/17/5587.abstract01798nas a2200181 4500008004100000022001400041245013300055210006900188300001400257490000700271520112900278653003201407100001701439700002101456700002201477700001701499856010001516 2006 eng d a1087-184500aGenetic characterization of the natural hybrid species Phytophthora alni as inferred from nuclear and mitochondrial DNA analyses0 aGenetic characterization of the natural hybrid species Phytophth a511 - 5290 v433 a

The different subspecies of Phytophthora alni, P. alni subsp. alni (Paa), P. alni subsp. uniformis (Pau), and P. alni subsp. multiformis (Pam), are recent and widespread pathogens of alder in Europe. They are believed to be a group of emergent heteroploid hybrids between two phylogenetically close Phytophthora species. Nuclear and mitochondrial DNA analyses were performed, using a broad collection of P. alni and two closely related species, P. cambivora and P. fragariae. (Paa) possesses three different alleles for each of the nuclear genes we studied, two of which are present in Pam as well, whereas the third matches the single allele present in Pau. Moreover, Paa displays common mtDNA patterns with both Pam and Pau. A combination of the data suggests that Paa may have been generated on several occasions by hybridization between Pam and Pau, or their respective ancestors. Pau might have P. cambivora as a species ancestor, whereas Pam seems to have either been generated itself by an ancient reticulation or by autopolyploidization.

10aInterspecific hybridization1 aIoos, Renaud1 aAndrieux, Axelle1 aMarÁais, BenoÓt1 aFrey, Pascal uhttp://www.sciencedirect.com/science/article/B6WFV-4JS1TK3-1/2/aead0efc6dc22a393ebadec5b3211855