Develop verticillium stripe disease management strategy in canola
Term: 3 years
Status: Ongoing
Researcher(s): Wei Xiao, Lipu Wang, U of S; Dilantha Fernando, U of M; Jie Feng, Alberta Ag & Forestry
SaskOilseeds Investment: $155,250
Total Project Cost: $672,000
Funding Partners: WGRF
Objective
Screen resistant alleles to Verticillium Stripe by using a susceptibility (S) gene strategy.
Project Description
Verticillium stripe is an important vascular disease of canola caused by the soilborne fungus Verticillium longisporum. This disease was well established in Europe decades ago and has subsequently been reported in other major oilseed growing regions.
In Canada, verticillium stripe was first found in Manitoba in 2014 and then rapidly spread across western Canada. Depending on the environmental conditions, yield losses in oilseed rape caused by V. longisporum have been estimated to range between 10% and 50%.
The management of verticillium stripe is challenging, as current disease control strategies do not provide appropriate protection. For example, there are no foliar or seed treatments available to control this disease, and no commercial canola is considered to be resistant. Furthermore, with its recent appearance in Canada, there exists
a significant dearth of information concerning the dissemination of verticillium stripe across western Canada and its acclimatization to the climate conditions of the Prairies. In this proposed project, we aim to address four important questions on verticillium stripe and develop an efficient disease management strategy to control this disease.
1. Identify resistance source using the Susceptibility (S) gene strategy.
The resistance to V. longisporum in canola is not governed by major genes, such as the Resistance (R) gene; but rather it is modulated by minor genes. This makes it difficult to identify and introgress those genes into the canola genotypes. So far, there is no resistant variety available for Canadian canola growers. Thus, it is needed to seek a resistance source to improve verticillium resistance in canola.
Different from R-gene-mediated disease resistance, a new alternative strategy based on susceptibility (S) genes has been proposed as they have the potential to be more durable in the field. The S genes can function as either suppressors of immunity or as crucial compatibility factors necessary for successful pathogen infection. While R genes are mostly dominant, the disease resistance provided by the manipulation of S genes is mostly recessive.
Therefore, broad-spectrum disease resistance can be readily conferred by disrupting S genes via precise genome-editing tools. Several potential robust S genes have been identified and successfully applied to major crops.
In previous projects, our lab has developed a S gene-based screening strategy and breeding method. This method has been successfully applied to characterize clubroot susceptibility factors and identify resistant mutant alleles against clubroot infection. In this new project, we will use this well-established screening/breeding strategy to identify verticillium susceptibility (VS) genes and screen mutant alleles to enhance resistance against the verticillium stripe disease.