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Title: EXAMINATION OF GENETIC DIVERSITY IN GEOGRAPHICALLY DISTINCT POPULATIONS OF PHYTOPHTORA INFESTANS

Author
item Deahl, Kenneth
item BLACK, L. - AVRDC, TAIWAN
item COOKE, L. - QUEENS UNIV,N. IREL.
item FORBES, G. - CIP, QUITO, ECUADOR
item SHAW, D. - UNIVERSITY OF WALES

Submitted to: European Association for Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The diversity in mitochondrial DNA (mtDNA) was assessed within putative clonal and sexual populations of the late blight pathogen, Phytophthora infestans. Studying the mitochondrial genome provides new information about the evolution of this species, taking advantage of the fact that some regions of the genome are under more stringent selective pressure than others. Monosporangial P. infestans isolates (n=317) collected in 1998-2001 (characterized previously for mating type, metalaxyl sensitivity, alleles at the glucose-6-phosphate isomerase locus and RFLP bands detected by probe RG57) were analyzed for mtDNA haplotype. Strains were obtained from naturally-infected hosts including potato (cultivated and wild Solanum species), tomato, woody and hairy nightshade, tree tomato and pepino. Every isolate tested (n-37) from central Mexico had a different RG57 fingerprint, but only mtDNA haplotype 1a was found. Other countries where isolates were exclusively of the 1a haplotype were Lebanon (n=12); Indonesia (n=2) and Costa Rica (n=6) Only the 1b haplotype was isolated in Npal (n=2) and only 11a in Uruguay (n=25). A shift from 1b to 11b was detected among Taiwan isolates (n=86). Two haplotypes were found in Wales (1a, 11a) and in Morocco (1a, 1b) and three in the United States (1a, 11a, 11b), Ecuador (1a, 1b, 11a) and Northern Ireland (1a, 11a, 11b). Additional sampling may help to unravel historical and recent migrations as well as providing new insights into the forces shaping diversity in populations.