Submitted to: Proceedings of the Oomycete Molecular Genetics Network
Publication Type: Abstract Only
Publication Acceptance Date: February 10, 2006
Publication Date: May 1, 2006
Citation: Grunwald, N.J. 2006. Population biology of the oomycete aphanomyces euteiches: a hierarchical analysis of diversity, selfing and genetic differentiation. Proceedings of the Oomycete Molecular Genetics Network. p.30. Technical Abstract: Relatively little is known about the population biology of the legume pathogen Aphanomyces euteiches Drechs. A. euteiches is a soilborne pathogen causing Aphanomyces root rot of several legumes including alfalfa, bean, lentil and pea. Our objectives were to assess the degree of diversity, selfing and population differentiation in A. euteiches, contrasting populations within and among two geographically separated fields with a history of pea production. Molecular genotyping relied on amplified fragment length polymorphism analysis. Samples of A. euteiches recovered from two fields in northeast Oregon and western Washington confirm previous reports of moderately high genetic diversity in populations of A. euteiches at the regional scale, but reveal higher than expected genotypic diversity within individual soil samples. Populations of A. euteiches were significantly differentiated at the soil sample, field and regional level. While most variation was seen at the regional scale, considerable variation was present at the level of the soil sample. The population structure appears to be patterned by regular selfing via oospores, a mixed reproductive system including both asexual and sexual reproduction, with occasional migration of novel genotypes or outcrossing.