Aphanomyces root rot is caused by the alfalfa pathogen Aphanomyces euteiches and similar to Phytophthora root rot (Phytophthora medicaginis) it is considered a major disease of alfalfa seedlings and adult plants. The incidence of Aphanomyces in the mid-west and northeastern United States has increased in recent years and has recently been confirmed in Ontario. These observations are of great concern since variety genetic resistance or tolerance has been the cornerstone of disease management in alfalfa production systems in Ontario. Race 1 resistant varieties and the more recent development of race 2 resistant varieties are available and a rapid diagnostic test would be beneficial to OMAFRA and the Ontario Forage Council monitoring and education efforts for Aphanomyces and other alfalfa diseases in Ontario.
A greenhouse differential assay has been developed for Aphanomyces and modified for Ontario by OMAFRA and the Ontario Forage Council but results can be influenced by external factors such as greenhouse conditions, etc. The purpose of this project was for OMAFRA and the Ontario Forage Council to link with the substantial resources of the Agriculture and Agri-Food Canada biodiversity-bioinformatics cluster in Ottawa led by Dr. Andre Levesque to compare published PCR and novel 454 molecular sequencing technologies for Aphanomyces euteiches and determine applicability of these methods into commercially available plant and soil diagnostic tests for producers.