Submitted to: Journal of Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 1/31/2006
Publication Date: 4/20/2006
Citation: Schroeder, K.L., Paulitz, T.C. 2006. quantification of pythium species in soils from dryland cereal-based cropping systems using real-time pcr.. Journal of Phytopathology. Vol.96: 637-647.
Technical Abstract: At least ten species of Pythium commonly occur in agricultural soils in eastern Washington. The cropping systems in these dryland areas are based on cereals, with rotation crops including several legumes and brassicas. Given the complex and diverse Pythium species composition, variation in species prevalence at different locations may depend on host crop and environment. A replicated field trial with cereals and five different rotation crops was sampled, as well as a survey of grower fields containing a variety of host crops. In both studies, soils were collected and real-time PCR was used to quantify ten species of Pythium. In the replicated trial, P. abappressorium, P. irregulare group IV and P. rostratifingens were the most commonly identified, with DNA concentrations of P. irregulare group IV 5- to 10-fold higher than the other species. Concentrations of Pythium DNA were similar with regard to host, except for reduced concentrations of P. rostratifingens DNA with lentil or fallow soil. In the survey, up to nine species of Pythium were found at a single location. P. irregulare group IV and P. abappressorium were observed most frequently (greater than 75% of locations), while more virulent species such as P. irregulare group I and P. ultimum occurred in fewer than 40% of the sites. P. irregulare group I was found only in soils from wheat and lentil fields.