scholarly journals A Global Marker Database for Phytophthora infestans

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 811-818 ◽  
Author(s):  
Gregory A. Forbes ◽  
Stephen B. Goodwin ◽  
André Drenth ◽  
Pedro Oyarzun ◽  
Maria Eugenia Ordoñez ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Fragment Length Polymorphism ◽  
Multilocus Genotypes ◽  
Mitochondrial Dna Haplotype ◽  
Late Blight Pathogen ◽  
Country Code ◽  
Allozyme Genotype

A marker database was compiled for isolates of the potato and tomato late blight pathogen, Phytophthora infestans, originating from 41 locations which include 31 countries plus 10 regions within Mexico. Presently, the database contains information on 1,776 isolates for one or more of the following markers: restriction fragment length polymorphism (RFLP) “fingerprint” consisting of 23 bands; mating type; dilocus allozyme genotype; mitochondrial DNA haplotype; sensitivity to the fungicide metalaxyl; and virulence. In the database, 305 entries have unique RFLP fingerprints and 258 entries have unique multilocus genotypes based on RFLP fingerprint, dilocus allozyme genotype, and mating type. A nomenclature is described for naming multilocus genotypes based on the International Organization for Standardization (ISO) two-letter country code and a unique number. Forty-two previously published multilocus genotypes are represented in the database with references to publications. As a result of compilation of the database, seven new genotypes were identified and named. Cluster analysis of genotypes from clonally propagated populations worldwide generally confirmed a previously published classification of “old” and “new” genotypes. Genotypes from geographically distant countries were frequently clustered, and several old and new genotypes were found in two or more distant countries. The cluster analysis also demonstrated that A2 genotypes from Argentina differed from all others. The database is available via the Internet, and thus can serve as a resource for Phytophthora workers worldwide.

scholarly journals Host Specificity of Phytophthora infestans on Tomato and Potato in Ecuador

1998 ◽  
Vol 88 (3) ◽  
pp. 265-271 ◽  
Author(s):  
P. J. Oyarzun ◽  
A. Pozo ◽  
M. E. Ordoñez ◽  
K. Doucett ◽  
G. A. Forbes
Keyword(s):  
Phytophthora Infestans ◽  
Mating Type ◽  
Clonal Lineage ◽  
Avirulence Genes ◽  
Mitochondrial Dna Haplotype ◽  
Different Populations ◽  
Tomato Cultivars ◽  
Globally Distributed ◽  
Allozyme Genotype ◽  
Specific Virulence

Sixty Ecuadorian isolates of Phytophthora infestans from potato and 60 isolates from tomato were compared for dilocus allozyme genotype, mitochondrial DNA haplotype, mating type, and specific virulence on 11 potato R-gene differential plants and four tomato cultivars, two of which contained different Ph genes. Restriction fragment length polymorphism (RFLP) fingerprints of subsamples of isolates from each host were compared by using RG57 as the probe. All potato isolates had the allozyme genotype, haplotype, and mating type of the clonal lineage EC-1, which had been previously described in Ecuador. With the same markers, only one isolate from tomato was classified as EC-1; all others belonged to the globally distributed US-1 clonal lineage. RFLP fingerprints of isolate subsets corroborated this clonal lineage classification. Specific virulence on potato differentials was broadest among potato isolates, while specific virulence on tomato cultivars was broadest among tomato isolates. Some tomato isolates infected all tomato differentials but no potato differentials, indicating that specific virulence for the two hosts is probably controlled by different avirulence genes in P. infestans. In two separate experiments, the diameters of lesions caused by nine isolates from potato and 10 from tomato were compared on three tomato and three potato cultivars. All isolates produced larger lesions on the host from which they were isolated. No isolates were found that were highly aggressive on both tomato and potato. We conclude that there are two different populations of P. infestans in Ecuador and that they are separated by host.

scholarly journals Complete mitogenome mapping of potato late blight pathogen, Phytophthora infestans A2 mating type

2017 ◽  
Vol 2 (1) ◽  
pp. 90-91
Author(s):  
Virupaksh U. Patil ◽  
G. Vanishree ◽  
Debasis Pattanayak ◽  
Sanjeev Sharma ◽  
Vinay Bhardwaj ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Potato Late Blight ◽  
Complete Mitogenome ◽  
Late Blight Pathogen

scholarly journals Characterization of Phytophthora infestans in Wisconsin from 1993 to 1995

Plant Disease ◽  
1998 ◽  
Vol 82 (4) ◽  
pp. 434-436 ◽  
Author(s):  
K. D. Marshall-Farrar ◽  
M. McGrath ◽  
R. V. James ◽  
W. R. Stevenson
Keyword(s):  
Solanum Tuberosum ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Production Problem ◽  
Significant Production ◽  
Allozyme Genotype ◽  
Late Blight Of Potato

Late blight of potato (Solanum tuberosum), caused by Phytophthora infestans, recently reappeared in Wisconsin and was a significant production problem in 1994. P. infestans isolates collected in Wisconsin from 1993 to 1995 were characterized for the following traits: mating type, sensitivity to metalaxyl, and allozyme genotype for Glucose-6-phosphate isomerase (Gpi). Characterization of these isolates revealed that a new, more aggressive population (A2 mating type, metalaxyl resistant, and Gpi genotype 100/111/122) is displacing the old population (A1 mating type, metalaxyl sensitive, and Gpi genotype 86/100) in Wisconsin.

scholarly journals A Novel Population of Phytophthora, Similar to P. infestans, Attacks Wild Solanum Species in Ecuador

2000 ◽  
Vol 90 (2) ◽  
pp. 197-202 ◽  
Author(s):  
M. E. Ordoñez ◽  
H. R. Hohl ◽  
J. A. Velasco ◽  
M. P. Ramon ◽  
P. J. Oyarzun ◽  
...  
Keyword(s):  
Mating Type ◽  
Fragment Length Polymorphism ◽  
Solanum Species ◽  
Its2 Sequence ◽  
Internal Transcribed Spacer Region ◽  
Primary Host ◽  
Wild Solanum Species ◽  
Mitochondrial Dna Haplotype ◽  
Global Movements ◽  
The Village

Twenty-six isolates of a Phytophthora population from two wild solanaceous species, Solanum tetrapetalum (n 11) and S. brevifolium (n = 15), were characterized morphologically, with genetic and phenotypic markers, and for pathogenicity on potato and tomato. Based on morphology, ribosomal internal transcribed spacer region 2 (ITS2) sequence, and pathogenicity, all isolates closely resembled P. infestans and were tentatively placed in that species. Nonetheless, this population of Phytophthora is novel. Its primary host is neither potato nor tomato, and all isolates had three restriction fragment length polymorphism (RFLP) bands (probe RG57) and a mitochondrial DNA haplotype that have not been reported for P. infestans. All the isolates were the A2 mating type when tested with a P. infestans A1 isolate. The A2 mating type has not been found among isolates of P. infestans from potato or tomato in Ecuador. Geographical substructing of the Ecuadorian A2 population was detected. The three isolates from the village of Nono, identical to the others in all other aspects, differed by three RFLP bands; those from Nono lacked bands 10 and 16, but possessed band 19. Most of the Ecuadorian A2 isolates were nonpathogenic on potato and tomato, but a few caused very small lesions with sparse sporulation on necrotic tissue. Cluster analysis of multilocus genotypes (RFLP, mating type, and two allozymes) dissociated this A2 population from genotypes representing clonally propagated populations of P. infestans worldwide. The current hypotheses for the historical global movements of P. infestans do not satisfactorily explain the origin or possible time of introduction into Ecuador of this A2 population. Assuming the population is P. infestans, its presence in Ecuador suggests either a hitherto unreported migration of the pathogen or an indigenous population that had not previously been detected.

scholarly journals Characterization of Isolates of Phytophthora infestans from Southern and Southeastern Brazil from 1998 to 2000

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 896-900 ◽  
Author(s):  
Ailton Reis ◽  
Christine D. Smart ◽  
William E. Fry ◽  
Luiz A. Maffia ◽  
Eduardo S. G. Mizubuti
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Fragment Length Polymorphism ◽  
Southeastern Brazil ◽  
Mating Types ◽  
Clonal Lineage ◽  
Metalaxyl Resistance ◽  
Restriction Fragment Length

The population of Phytophthora infestans in Brazil was first characterized 12 years ago. In this research, isolates of P. infestans from potato (n = 184) and tomato (n = 267) collected in southern and southeastern Brazil were characterized to provide more detailed analysis of the current structure of the population. All 451 isolates were analyzed for mating type, and subsets of the isolates were analyzed for allozymes, restriction fragment length polymorphism fingerprint, mtDNA haplotypes, and metalaxyl resistance. Tomato isolates were all of A1 mating type, mtDNA Ib, and US-1 genotype or some variant within this clonal lineage. Of the potato isolates, 82% were A2 mating type, mtDNA IIa, BR-1 genotype, which is a new lineage of P. infestans. All A2 isolates were found on potato, whereas 91% of the A1 isolates were from tomato. A1 and A2 isolates were never found in the same field. The frequency of resistance to metalaxyl was higher in isolates from tomato (55%) than in isolates from potato (38%). After more than a decade of coexistence of isolates of the A1 and A2 mating types, the population was highly clonal, dominated by the BR-1 and US-1 clonal lineages.

scholarly journals Genetic Structure of Peruvian Populations of Phytophthora infestans

2001 ◽  
Vol 91 (10) ◽  
pp. 956-965 ◽  
Author(s):  
Willmer G. Perez ◽  
J. Soledad Gamboa ◽  
Yesenia V. Falcon ◽  
Mario Coca ◽  
Rubi M. Raymundo ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Peruvian Andes ◽  
The North ◽  
Metalaxyl Sensitivity ◽  
Andean Countries ◽  
Key Sites ◽  
Late Blight Pathogen

Isolates of the late blight pathogen Phytophthora infestans (n = 327) from the central to southern Peruvian Andes were systematically collected in 1997 to 1999 and analyzed to determine the pathogen's population structure at its host's center of diversity. No isolates of the A2 mating type were detected. Cluster analysis of DNA fingerprinting data indicated that the collection consisted of five major groups that were interpreted to be clonal lineages. Two of the lineages (US-1 and EC-1) have been previously described, and three (PE-3, 5, and 6) are described here for the first time. Collections from three areas in the central Peruvian Andes, including two key sites used in an international potato breeding program, consisted of isolates of the EC-1 lineage, which has been reported to dominate the pathogen population in Andean countries to the north of Peru. The collections from Cusco and Puno were more diverse. More than one lineage was detected in 10 of the 20 fields sampled in Cusco. Data on virulence, metalaxyl sensitivity, and band data for allozymes, mitochondrial DNA, and ipiB1 suggested that PE-3 may have been produced through recombination events between US-1 and EC-1. Restriction fragment length polymorphism and amplified fragment length polymorphism marker data were not consistent with this hypothesis.

scholarly journals Characterization of South African Isolates of Phytophthora infestans

Plant Disease ◽  
2001 ◽  
Vol 85 (3) ◽  
pp. 287-291 ◽  
Author(s):  
A. McLeod ◽  
S. Denman ◽  
A. Sadie ◽  
F. D. N. Denner
Keyword(s):  
Phytophthora Infestans ◽  
Mating Type ◽  
Coastal Region ◽  
Potato Production ◽  
Screening Tests ◽  
Sensitivity Testing ◽  
Fingerprint Pattern ◽  
Metalaxyl Sensitivity ◽  
Mitochondrial Dna Haplotype

Severe late blight epidemics in South Africa in 1995 and 1996 prompted an investigation into the mating type, genotype, and metalaxyl sensitivity of populations of Phytophthora infestans. A country-wide survey was conducted from 1996 to 1998 in which isolates were collected from 101 potato fields (656 isolates) and 16 tomato fields (57 isolates). Six hundred and fifty-seven isolates (600 potato and 57 tomato) were analyzed for mating type, while subsets of isolates were analyzed for genotype at the Glucose-6-phosphate isomerase locus (n = 148), DNA fingerprinting with probe RG-57 (n = 61) and mitochondrial DNA haplotype (n = 20). All isolates tested had the characteristics typical of the pre-1980 population (A1 mating type, 86/100 Gpi genotype, US-1 fingerprint pattern, and mtDNA haplotype I-b) previously found worldwide. Metalaxyl sensitivity testing of 656 potato isolates by the in vitro leaf disk method showed that the frequency of highly resistant isolates (50% effective concentration [EC50] > 200 μg a.i./ml) in potato production regions increased from 35% in 1996 to 51% in 1997. The high frequency of resistant isolates was confined to the southern coastal regions in 1996 and 1997, as well as the western Free State in 1997. Although phenylamides were withdrawn from the southern coastal region in December 1996, screening tests carried out in 1998 indicated that resistance levels remained high (≥83%). Sensitive isolates (EC50 < 40 μg a.i./ml) predominated in the remaining six potato production regions. Screening of 45 isolates collected from tomatoes indicated that no resistant strains were present in the sample tested.

Incidence of the potato late blight pathogen, Phytophthora infestans, in Syria and its mating type

2017 ◽  
Vol 124 (6) ◽  
pp. 533-537 ◽  
Author(s):  
Walid Naffaa ◽  
Soulima Ibrahim ◽  
Taissir Abou Alfadil ◽  
Antonious Al-Daoude
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Potato Late Blight ◽  
Late Blight Pathogen

An improved PCR method for rapid and accurate identification of mating types in the late blight pathogen Phytophthora infestans

2021 ◽  
Author(s):  
Romain Mabon ◽  
Michèle Guibert ◽  
Roselyne Corbiere ◽  
Didier Andrivon
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Multiplex Pcr ◽  
Mating Type ◽  
Mating Types ◽  
Accurate Identification ◽  
Fta Cards ◽  
Multiplex Pcr Assay ◽  
Freeze Dried ◽  
Late Blight Pathogen

Mating type is a critical trait in heterothallic organisms. In plant pathogenic oomycetes, like the late blight pathogen Phytophthora infestans, it is usually identified through pairing between tester and candidate isolates, a method which is both laborious and applicable to live isolates only. Therefore, developing simple and fast PCR tests to reliably identify P. infestans mating types is of great interest for population genetic studies. A multiplex PCR assay combining the amplification of a locus diagnostic for P. infestans and of one diagnostic for the A1 mating type was developed and validated on a collection of 1441 samples, covering the current and past diversity of European P. infestans populations. These samples obtained from either freeze-dried mycelium or from FTA cards on which diseased leaflets had been pressed. The multiplex assay correctly identified mating types in 97.4 % of these samples. The main source of incorrect assignment was the lack of amplification of the A1 diagnostic allele, due to insufficient DNA quality and/or quantity in the reaction mix. This multiplex PCR, applicable to both live and stored material, thus constitutes a useful addition to the set of molecular tools available for population typing in P. infestans.

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