Phytophthora taxa associated with cultivated Agathosma, with emphasis on the P. citricola complex and P. capensis sp. nov.
Abstract:Agathosma species, which are indigenous to South Africa, are also cultivated for commercial use. Recently growers experienced severe plant loss, and symptoms shown by affected plants suggested that a soilborne disease could be the cause of death. A number of Phytophthora taxa were isolated from diseased plants, and this paper reports their identity, mating type, and pathogenicity to young Agathosma plants. Using morphological and sequence data seven Phytophthora taxa were identified: the A1 mating type of P. cinnamomi var. cinnamomi, P. cinnamomi var. parvispora and P. cryptogea, the A2 mating type of P. drechsleri and P. nicotianae, and two homothallic taxa from the P. citricola complex. The identity of isolates in the P. citricola complex was resolved using reference isolates of P. citricola CIT groups 1 to 5 sensu Oudemans et al. (1994) along with multi-locus phylogenies (three nuclear and two mitochondrial regions), isozyme analyses, morphological characteristics and temperature-growth studies. These analyses revealed the isolates from Agathosma to include P. multivora and a putative novel species, P. taxon emzansi. Furthermore, among the P. citricola reference isolates the presence of a new species was revealed, described here as P. capensis. Findings of our study, along with some recent other studies, have contributed to resolving some of the species complexity within the P. citricola complex, resulting in the identification of a number of phylogenetically distinct taxa. The pathogenicity of representative isolates of the taxa from Agathosma was tested on A. betulina seedlings. The putative novel species, P. taxon emzansi, and P. cinnamomi var. parvispora were non-pathogenic, whereas the other species were pathogenic to this host.
Document Type: Research Article
Publication date: December 23, 2010
More about this publication?
- Persoonia aims to publish papers dealing with molecular phylogeny and evolution of fungi. A further aim is to promote fungal taxonomy by employing a polythetic approach to clarify the true phylogeny and relationships within the kingdom Fungi. The journal publishes high-quality papers elucidating known and novel fungal taxa at the DNA level, and also strives to present novel insights into evolutionary processes and relationships. Papers to be considered include research articles, topical and book reviews.
Papers are published using a Fast Track system. This implies that the papers are immediately published online and freely available through the internet via this website. For effective publication under the International Code of Botanical Nomenclature the online published papers will be distributed in printed form to several libraries at the same time.
Hard copy volumes: Twice a year (June and December) the online published papers will be bound. These volumes new style will be in A4 format and full colour and will be available through the Publications Department of the National Herbarium of the Netherlands.
Persoonia is a journal published jointly by the Nationaal Herbarium Nederland and the Centraalbureau voor Schimmelcultures.
Fast Track articles are available here
If there are no articles shown in this section, all the Fast Track articles are published in the latest issue of Persoonia.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Back issues for Persoonia
- Persoonia Supplement Series
- Ingenta Connect is not responsible for the content or availability of external websites