title: Putative natural hybrid between Puccinia lagenophorae and an unknown rust fungus on Senecio madagascariensis in KwaZulu-Natal, South Africa.
abstract: Several specimens of an aecial rust fungus were collected on Senecio madagascariensis during a field survey carried out in KwaZulu-Natal, South Africa. As telia were not present in the specimens collected, DNA sequence analyses were undertaken to determine the identity of the rust species. ITS and beta-tub1 sequencing confirmed that one of the isolates recovered is Puccinia lagenophorae sensu lato. On the other hand, sequencing and RFLP analysis revealed the presence of two divergent copies of ITS and beta-tub1 in all the other six isolates investigated. In both phylogenetic trees, one copy of the gene region grouped within a well supported clade with sequences of P. lagenophorae accessions from different geographical origins and hosts, and the Australian rusts Puccinia saccardoi and Puccinia stylidii. The other copy of these gene regions grouped within a separate clade comprising European accessions of Puccinia dioicae (ITS) and Uromyces sommerfeltii (beta-tub1) that occur on Asteraceae hosts. Multiple copies of these gene regions were not observed in Australian isolates of P. lagenophorae. Our study provides some evidence that an interspecific hybrid rust fungus, with P. lagenophorae as one of its parents, may occur on S. madagascariensis in South Africa. The identity of the other parent remains unknown.
authors.affiliation: CSIRO Entomology, Cooperative Research Centre for Australian Weed Management, GPO Box 1700, Canberra, Australian Capital Territory 2601, Australia. louise.morin@csiro.au
authors.forename: Louise
authors.initials: L
authors.lastname: Morin
authors.forename: Marlien
authors.initials: M
authors.lastname: van der Merwe
authors.forename: Diana
authors.initials: D
authors.lastname: Hartley
authors.forename: Petra
authors.initials: P
authors.lastname: Müller
mesh_terms: D001487:Basidiomycota / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D002678:Chimera / Q000145:classification / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D006824:Hybridization, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D012674:Senecio / Q000382:microbiology*; D013019:South Africa; D014404:Tubulin / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D005656:Fungal Proteins; D014404:Tubulin