Abstract
Isozyme analysis and sequence analysis of the internal transcribed spacer regions (ITS-1 and ITS-2) and the 5.8S subunit of the ribosomal DNA gene repeat were used to examine whether isolates of Phytophthora porri from Allium and Brassica represent a single homogeneous species. Twenty-six strains of P. porri, 16 strains isolated from the genus Allium, and 10 strains isolated from the genus Brassica, were analyzed using malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH) and lactate dehydrogenase (LDH), represented altogether by four putative loci (Mdh-2, Idh-1, Idh-2, and Ldh-2). Isozyme analysis revealed that strains isolated from Allium contained five private alleles at three isozyme loci (Ldh-2 83, Ldh-2 104, Idh-1 108, Idh-1 112, and Idh-2 98), whereas six different alleles were observed at four isozyme loci (Ldh-2 85, Ldh-2 100, Ldh-2 114, Idh-1 100, Idh-2 100, and Mdh-2 111) in strains obtained from Brassica. The heterozygosity at the Ldh-2 locus, differing in allele composition, however, between strains from Allium and Brassica, was present in all strains, indicating that it is probably fixed. Sequence analysis of the ITS regions and the 5.8S subunit showed consistent differences between isolates from Allium and isolates from Brassica. Based on isozyme data, ITS sequence analysis and formerly published differences in restriction enzyme patterns of mitochondrial DNA, morphology and pathogenicity, it was concluded that the isolates of P. porri Foister did not represent a homogeneous species. Isolates from Brassica constitute a distinct species which is described here as P. brassicae sp. nov. It was inferred from isozyme patterns, which were in no case intermediate between the two species, that P. porri and P. brassicae do not hybridize and are reproductively isolated by barriers to gene flow.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bakkeren G, Kronstad JW and Lévesque CA (2000) Comparison of AFLP fingerprints and ITS sequences as phylogenetic markers in Ustilaginomycetes. Mycologia 92: 510–521
Brasier CM, Cooke DEL and Duncan JM (1999) Origin of a new Phytophthora pathogen through interspecific hybridization. Proceedings of the National Academy of Sciences USA 96: 5878–5883
De Cock WAM, Neuvel A, Bahnweg G, de Cock JCJM and Prell HH (1992) A comparison of morphology, pathogenicity and restriction fragment patterns of mitochondrial DNA among isolates of Phytophthora porri Foister. Netherlands Journal of Plant Pathathology 98: 277–289
Cooke DEL and Duncan JM (1997) Phylogenetic analysis of Phytophthora species based on ITS 1 and ITS 2 sequences of the ribosomal RNA gene repeat. Mycological Research 101: 667–677
Cooke DEL, Jung T, Williams NA, Schubert R, Bahnweg G, Osswald W and Duncan JM (1999) Molecular evidence supports Phytophthora quercina as a distinct species. Mycological Research 103: 799–804
Cooke DEL, Drenth A, Duncan JM, Wagels G and Brasier CM (2000) A molecular phylogeny of Phytophthora and related Oomycetes. Fungal Genetics and Biology 30: 17–32
Erwin DC and Ribeiro OK 1996. Phytophthora Diseases Worldwide. APS Press: Minnesota
Foister CE (1931) The white tip disease of leeks and its causal fungus, Phytophthora porri n.sp. Transactions of the Botanical Society of Edinburgh 30: 257–281
Gams W, Hoekstra ES and Aptroot A (eds) (1998) CBS Course of Mycology, 4th edn. Centraalbureau voor Schimmelcultures, Baarn/Delft
Goodwin SB, Spielman LJ, Matuszak JM, Bergeron SN and Fry WE (1992) Clonal diversity and genetic differentiation of Phytophthora infestans populations in Northern and Central Mexico. Phytopathology 82: 955–961
Goodwin SB, Legard DE, Smart CD, Levy M and Fry WE (1999) Gene flow analysis of molecular markers confirms that Phytophthora mirabilis and Phytophthora infestans are separate species. Mycologia 91: 796–810
Goodwin SB, Webster RK and Allard RW (1994) Evidence for mutation and migration as sources of genetic variation in populations of Rhynchosporium secalis. Phytopathology 84: 1047–1053
Hansen EM (1991) Variation in the species of the Phytophthora megasperma complex. In: Lucas JA, Shattock RC, Shaw DS, Cooke LR (eds) Phytophthora (p 157) Cambridge University Press, Cambridge
Ilieva E, Man in' t Veld WA, Veenbaas-Rijks W and Pieters R (1998) Phytophthora multivesiculata, a new species causing rot in Cymbidium. European Journal of Plant Pathology 104: 677–684
Jung T, Cooke DEL, Blaschke H, Duncan JM, Osswald W (1999) Phytophthora quercina sp. nov., causing rot of European oaks. Mycological Research 103: 785–798
Von Maltitz PA and von Broembsen SL (1984) Phytophthora porri on onions in South Africa. Plant Disease 68: 732
Man in' t Veld WA, Veenbaas-Rijks WJ, Ilieva E, de Cock AWAM, Bonants PJM and Pieters R (1998) Natural hybrids of Phytophthora nicotianae and Phytophthora cactorum demonstrated by isozyme analysis and Random Amplified Polymorphic DNA. Phytopathology 88: 922–929
Mchau GRA and Coffey MD (1994) Isozyme diversity in Phytophthora palmivora: evidence for a southeast Asian centre of origin. Mycological Research 98: 1035–1043
Möller EM, Bahnweg G, Sandermann H and Geiger HH (1992) A simple and efficient protocol for isolation of high molecular weight DNA from filamentous fungi, fruit bodies, and infected plant tissues. Nucleic Acids Research 20: 6115–6116
Möller EM, de Cock AWAM and Prell HH (1993) Mitochondrial and nuclear DNA restriction enzyme analysis of the closely related Phytophthora species P. infestans, P. mirabilis and P. phaseoli. Journal of Phytopathology 139: 309–321
Oudemans P and Coffey MD (1991) A revised systematics of twelve papillate Phytophthora species based on isozyme analysis. Mycological Research 95: 1025–1046
Richardson BJ, Baverstock PR and Adams M (1986) Electrophoresis. In: Allozyme Electrophoresis (p 23) Academic Press, New York
Roux P and Labarère J (1991) Determination of genes and subunit composition of three isozyme activities in Agaricus bitorquis. Mycological Research 95: 851–860
Spielman LJ, Sweigadr JA, Shattock RC and Fry WE (1990) The genetics of Phytophthora infestans: Segregation of allozyme markers in F2 and backcross progeny and the inheritance of virulence against potato resistance R2 and R4 in F1 progeny. Experimental Mycology 14: 57–69
Stamps DJ, Waterhouse GM, Newhook FJ and Hall GS (1990) Revised tabular key to the species of Phytophthora, 2nd edn. Mycological Papers 162
Werres S, Marwitz R, Man in' t Veld WA, de Cock AWAM, Bonants PJM, de Weerdt M, Themann K, Ilieva E and Baayen RP (2001) Phytophthora ramorum sp. nov., a new pathogen on Rhododendron and Viburnum. Mycological Research 105(10): 1155–1165
Whisson S, Drenth A, Maclean DJ and Irwin JAG (1994) Evidence for outcrossing in Phytophthora sojae and linkage of a DNA marker to two avirulence genes. Current Genetics 27: 77–82
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Man in 't Veld, W.A., de Cock, A.W., Ilieva, E. et al. Gene Flow Analysis of Phytophthora porri Reveals a New Species: Phytophthora brassicae Sp. Nov.. European Journal of Plant Pathology 108, 51–62 (2002). https://doi.org/10.1023/A:1013929110325
Issue Date:
DOI: https://doi.org/10.1023/A:1013929110325