Author
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Deahl, Kenneth |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 8/24/2003 Publication Date: 11/24/2003 Citation: Deahl, K. 2004. Population dynamics of Phytophthora infestans assessed by mitochondrial DNA.[abstract] American Journal of Potato Research 81(1):54. Interpretive Summary: Technical Abstract: Late blight caused by the oomycete Phytophthora infestans, is the most destructive disease of potato cultivation worldwide. Novel strains of P. infestans have evolved which possess the potential to overcome genetic resistance introgressed by conventional breeding from wild potato species into commercial varieties. Future breeding efforts, both conventional and molecular, may be further endangered by the pathogenic capabilities of this organism, since many studies have provided evidence of worldwide migrations that have introduced new, more aggressive and virulent strains. Moreover, workers have recently detected an increase in genotypic diversity that may have resulted from sexual recombination of migrant genotypes. Characterization of mitochondrial DNA (mtDNA) haplotype may provide insights into the population dynamics of this pathogen in the US, not given by other phenotypic and genetic markers. Isolates collected from natural infections on potato and tomato hosts were characterized for frequency and distribution of four specific mtDNA haplotypes. Among the isolates collected over a 12 year period (1990-2002), three haplotypes, viz. Ia, Ib, IIb, were identified. Further examination of field isolates and comparison with archival strains can provide information on the population structure over time.This information is also important in revealing the primary sources of inoculum, the extent of gene flow among populations, and the modes of reproduction during epidemics. |
