| Crop | Pea |
|---|---|
| Start Date | 2013 |
| End Date | 2017 |
| Principal Investigator | McLaren, Debra, Agriculture and Agri-Food Canada |
| MPSG Financial Support | $55,000 |
| Total Project Funding | $193,100 |
| External Funding Partners | Agriculture and Agri‐Food Canada through the AgriInnovation Program |
Project Description
Root rot is a major disease of field pea across the Canadian prairies and causes yield losses by reducing plant stands and compromising root systems. Field surveys have demonstrated that Aphanomyces euteiches, Fusarium avenaceum and F. solani are prevalent across the Prairies and are highly virulent on pea. For example, almost all (39 of 40) of the commercial pea fields in Manitoba evaluated in 2015 had root rot. Planting resistant or tolerant cultivars would provide the best option for the long term management of root disease, but no cultivars with complete resistance are available. Despite the potential gains that might come from resistant / tolerant cultivars, little is known about the root rot reaction of the field pea cultivars currently grown in Canada. Inoculated field trials to assess the reactions of 60 field pea cultivars to three common root pathogens were conducted at field locations in Manitoba, and 20 cultivars were screened for disease reactions in naturally-infested fields in Saskatchewan and Alberta. Most of the cultivars were susceptible to seedling blight and root rot caused, but a few were resistant to one or more pathogens.
Aphanomyces root rot has been recognized as a problem in field pea production across western Canada. A few germplasm lines have been reported with tolerance. Progeny lines from crosses with the most tolerant lines of field peas were assessed in a genetic study at a field site where Aphanomyces root rot is uniform and severe. Field trials evaluating seed treatment products with active ingredients against Fusarium, Pythium, Rhizoctonia and A. euteiches were tested at several locations.
Rapid, accurate and sensitive identification of the most common root rot pathogens is needed to screen for host resistance and to develop best management practices. Molecular diagnostic procedures were developed for a number of pea root rot pathogens. For Aphanomyces, molecular markers that are tightly linked with genes for root rot tolerance are being developed for use in selection for disease tolerance, which will eventually be made available as new cultivars.
A tool for assessing the risk of severe root rot in a field is needed to limit the impact of the root rot complex. To develop this technology, information is first needed on the scope, cause and management options for root rot. The use of real-time PCR to assess fields for pathogen(s) and inoculum load is being investigated. If successful, this information will be used to determine if a field is at risk of root disease problems on field pea and so should be avoided. Inoculum dose-response curves were developed in greenhouse trials, correlating root rot severity with the DNA quantity of F. avenaceum inoculum. Samples of field soil are being assessed to determine if this relationship can be extended to samples from fields.