Assessment of pathogen variation for scald, net blotch, stripe rust and common root rot/spot blotch pathogens in response to geographic location, host genotype, host growth stage and specific host issues
Dr. T. Kelly Turkington
Agriculture and Agri-Food Canada
Timeline: April 2013 – March 2018
Alberta Barley funding: $63,052
Total funding from other partners: $229,287
Benefits for barley farmers
It is critical to have ongoing, up-to-date knowledge regarding the causal agents of the main disease issues that farmers face. This information is important for farmers because it will allow them to avoid cultivars with sources of resistance that are no longer effective, reducing the negative impact of disease on yield and quality.
Modern agriculture’s reliance on uniform cultivars, monocultures and rotations with limited diversity hinders efforts to manage pest issues, such as diseases. The lack of genetic diversity in modern cultivars is also frequently reflected in the narrowness of the genetic basis of their disease resistance, and increases the potential for pathogens to adapt, overcome the resistance and cause widespread epidemics. Trials were conducted in 2013 to assess the variability and nature of the pathogens that cause scald, net blotch and stripe rust in barley. Evaluation of scald reactions for older and previously resistant varieties indicate that the scald pathogen has adapted to the resistance in these varieties.
Trials were conducted in 2015 to assess the variability and nature of the pathogens that cause scald, net blotch and stripe rust of barley. In 2015, levels of scald were lower on Manny, and Sundre, which may be a reflection of less conducive weather conditions in 2015. There was limited scald development in the scald race variation test for 2015 as a result of drought conditions in central Alberta. Disease surveys were conducted during the summer of 2015. Growing conditions in central Alberta were poor in May and June with much lower than normal levels of precipitation, but with near average temperatures. In July and August conditions were near average for both precipitation and temperature. Disease development throughout the surveyed region was lower than found in previous years. Increased spot blotch in central Alberta was observed and this may temporarily reflect the prevailing weather conditions in 2015; the appearance of this disease has been noted over several years and this suggests it may warrant more effort in relation to surveying and screening barley varieties and germplasm in central Alberta. P. striiformis samples were collected from wheat, barley, foxtail barley and triticale from central Alberta in 2014 and 2015. Collection and purification of urediniospores from leaf samples and subsequent determination of forma specialis and virulence are underway.
Objectives for the upcoming year
Development of knowledge regarding the nature and variability of plant pathogens is critical for the successful development of barley cultivars with durable resistance. This information ensures that collaborating breeders and plant pathologists are screening germplasm and breeding lines against the most current, prevalent and/or virulent diseases and pathogen races. Moreover, detection of the extent and nature of pathogen diversity will indicate how rapidly pathogens can evolve in response to environmental and cropping system changes as well as fungicide use.
Last updated June 2016