Location of Repository

Characterization of Phytophthora hybrids from ITS clade 6 associated with riparian ecosystems in South Africa and Australia

By J.H. Nagel, M. Gryzenhout, B. Slippers, M.J. Wingfield, G.E.St.J. Hardy, M.J.C. Stukely and T.I. Burgess

Abstract

Surveys of Australian and South African rivers revealed numerous Phytophthora isolates residing in clade 6 of the genus, with internal transcribed spacer (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 (antisilencing factor (ASF) and G protein alpha subunit (GPA)), and one mitochondrial locus (cytochrome oxidase c subunit I (coxI)) were amplified and sequenced to test 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 different hybrid types involving the three described parent species Phytophthora amnicola, Phytophthora thermophila, and Phytophthora taxon PgChlamydo. In all cases, only a single coxI allele was detected, suggesting that hybrids arose from sexual recombination. All the hybrid isolates were sterile in culture and all their physiological traits tended to resemble those of the maternal parents. Nothing is known regarding their host range or pathogenicity. Nonetheless, as several isolates from Western Australia were obtained from the rhizosphere soil of dying plants, they should be regarded as potential threats to plant health. The frequent occurrence of the hybrids and their parent species in Australia strongly suggests an Australian origin and a subsequent introduction into South Africa

Publisher: Elsevier BV
Year: 2013
OAI identifier: oai:researchrepository.murdoch.edu.au:14820
Provided by: Research Repository

Suggested articles

Preview

Citations

  1. (2000). A Molecular Phylogeny of Phytophthora and Related Oomycetes.
  2. (1992). A simple and efficient protocol for isolation of high molecular weight DNA from filamentous fungi, fruit bodies, and infected plant tissues.
  3. (2011). Aberrant genome size and instability of Phytophthora ramorum oospore progenies.
  4. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics, in:
  5. (1993). An integrated approach to the analysis of variation in Phytophthora nicotianae and a redescription of the species.
  6. (1995). An unusual Phytophthora associated with widespread alder mortality in Britain.
  7. (2011). and ecological implications.
  8. (2001). Chromosomal rearrangements and speciation.
  9. (1985). Confidence limits on phylogenies: an approach using the bootstrap.
  10. (1995). Creation of species hybrids of Phytophthora with modified host ranges by zoospore fusion.
  11. (1993). Cultural characters, protein patterns and unusual mating behaviour of Phytophthora gonapodyides isolates from Britain and North America.
  12. (2008). Detecting Phytophthora ramorum and other species of Phytophthora in streams in natural ecosystems using baiting and filtration methods, in: Frankel
  13. (1974). Detection of Phytophthora cinnamomi in soils.
  14. (1995). Documentation of reticulate evolution in peonies (Paeonia) using internal transcribed spacer sequences of nuclear ribosomal DNA: implications for biogeography and concerted evolution.
  15. (2011). Endophytes as potential pathogens of the baobab species Adansonia gregorii: a focus on the Botryosphaeriaceae.
  16. (2008). Epigenetic, transposon and small RNA determinants of hybrid dysfunctions.
  17. (1985). Ethanol precipitation of DNA.
  18. (2000). False-negative isolations or absence of lesions may cause mis-diagnosis of diseased plants infected with Phytophthora cinnamomi.
  19. (2013). Fishing for Phytophthora from Western Australia's waterways: A distribution and diversity survey. Australasian Plant Pathology.
  20. (2012). Fungal Planet description sheets:
  21. (2006). Genetic characterization of the natural hybrid species Phytophthora alni as inferred from nuclear and mitochondrial DNA analyses.
  22. (2001). High frequency mitotic gene conversion in genetic hybrids of the oomycete Phytophthora sojae.
  23. (2004). In't Veld
  24. (2005). MAFFT version 5: improvement in accuracy of multiple sequence alignment.
  25. (2001). Managing critical transition zones.
  26. (2000). Managing Port-Orford-cedar and the introduced pathogen Phytophthora lateralis.
  27. (1990). Mating behavior of Phytophthora parasitica: Evidence for sexual recombination in oospores using DNA restriction fragment length polymorphisms as genetic markers.
  28. (2010). Meiotic versus mitotic recombination: Two different routes for double-strand break repair.
  29. (2000). Molecular characterization of natural hybrids of Phytophthora nicotianae
  30. (2009). Molecular comparison of natural hybrids of Phytophthora nicotianae and P. cactorum infecting loquat trees in Peru and Taiwan.
  31. (1993). Molecular taxonomy of Phytophthora megasperma based on mitochondrial and nuclear DNA polymorphisms.
  32. (2003). MrBayes 3: Bayesian phylogenetic inference under mixed models.
  33. (2004). MrModeltest version 2.2. Available from:
  34. (2003). Multiple new phenotypic taxa from trees and riparian ecosystems in Phytophthora gonapodyides-P. megasperma ITS clade 6, which tend to be high-temperature tolerant and either inbreeding or sterile.
  35. (1998). Natural hybrids of Phytophthora nicotianae and Phytophthora cactorum demonstrated by isozyme analysis and random amplified polymorphic DNA.
  36. (2007). Natural hybrids of resident and introduced Phytophthora species proliferating on multiple new hosts.
  37. (2012). New Phytophthoras in Western Australia's natural ecosystems.
  38. (2002). Non-Mendelian inheritance revealed in a genetic analysis of sexual progeny of Phytophthora cinnamomi with microsatellite markers.
  39. (2008). Occurrence and characterization of a Phytophthora sp. pathogenic to asparagus (Asparagus officinalis) in Michigan.
  40. (1999). Origin of a new Phytophthora pathogen through interspecific hybridization.
  41. (2002). PAUP*. Phylogenetic Analysis Using Parsimony (*and other methods). Version 4. Sinauer Associates,
  42. (1997). Persistent nuclear ribosomal DNA sequence polymorphism in the Amelanchier agamic complex (Rosaceae).
  43. (2003). Phylogenetic relationships among Phytophthora species inferred from sequence analysis of mitochondrially encoded cytochrome oxidase I and II genes.
  44. (2009). Phytophthora Biodiversity: How Many Phytophthora Species Are There?,
  45. (2002). Phytophthora disease of alder (Alnus glutinosa) in France: investigations between
  46. (2003). Phytophthora inundata sp. nov., a part heterothallic pathogen of trees and shrubs in wet or flooded soils.
  47. (2008). Phytophthora pinifolia sp. nov. associated with a serious needle disease of Pinus radiata in Chile.
  48. (1999). Phytophthora quercina sp. nov., causing root rot of European oaks.
  49. (2002). Phytophthora ramorum as the cause of extensive mortality of Quercus spp. and Lithocarpus densiflorus in California.
  50. (2011). Phytophthora species in forest streams in Oregon and Alaska.
  51. (2009). Phytophthora x pelgrandis, a new natural hybrid pathogenic to Pelargonium grandiflorum hort.
  52. (1986). Some probabilistic and statistical problems in the analysis of DNA sequences.
  53. (2012). Species of Phytophthora associated with a native ecosystem in Gauteng. MSc Thesis,
  54. (2003). Standard and Swedish variant types of the hybrid alder Phytophthora attacking alder in Hungary.
  55. (2005). The ‘asparagus’ Phytophthora infecting members of the Agavaceae at the Royal Botanic Gardens,
  56. (2012). The Phytophthora Genus Anno
  57. (2007). The Phytophthora species known as “PgChlamydo”, in:
  58. (2000). The rise of the hybrid fungi.
  59. (2005). The spores of Phytophthora: weapons of the plant destroyer.
  60. (1991). Touchdown' PCR to circumvent spurious priming during gene amplification.
  61. (2012). two destructive pathogens generated by natural hybridization. Mycologia 104:

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.