TreeBASE Search-Analyses for study 12996

@ARTICLE{TreeBASE2Ref21718, author = {Jan Hendrik Nagel and Marieka Gryzenhout and Bernard Slippers and Michael J Wingfield and Giles E. St.J. Hardy and Mike Stukely and Treena I Burgess}, title = {Characterization of Phytophthora hybrids from ITS clade 6 associated with riparian ecosystems in South Africa and Australia}, year = {2013}, keywords = {Phytophthora; ITS; coxI; Interspecific hybridization; Recombination}, doi = {}, url = {http://}, pmid = {}, journal = {Fungal Biology}, volume = {}, number = {}, pages = {}, abstract = {Surveys of Australian and South African rivers revealed numerous isolates of Phytophthora spp. residing in Clade 6 of the genus, which had ITS gene regions that were either highly polymorphic or unsequenceable. These isolates were suspected to be hybrids. Three nuclear loci, the ITS region, two single copy loci (ASF and GPA) and one mitochondrial locus (coxI) were amplified and sequenced to validate this hypothesis. Abundant recombination within the ITS region was observed. This, combined with phylogenetic comparisons of the other three loci, confirmed the presence of four distinct hybrids involving the three known parental species P. amnicola, P. thermophila and P. taxon PgChlamydo. In all cases, only a single coxI allele was obtained suggesting that hybrids arose from sexual recombination. The hybrid species were sterile in culture and had physiological traits similar to those of the maternal parents. Nothing is known regarding the host range or pathogenicity of these hybrids, but several isolates from Western Australia were obtained from the rhizosphere soil of dying plants. Regardless of the unknown pathogenicity of these hybrids, they should be regarded as potential threats. Their serendipitous and simultaneous discovery on two continents is intriguing yet their broad geographic distribution, frequent occurrence and their presence together with their parental strains in Australia strongly suggests an origin in this country. } }