Pathology

Overview

In the Pulse Crop Pathology Group we are interested in the biology of fungal and bacterial pathogens and their interaction with the legume host plants. The ultimate goal is to gain a better understanding of strategies employed by these pathogens to successfully invade and colonize pulse crops, and to exploit this knowledge for the purpose of developing resistant varieties and disease management strategies. The research program follows a hierarchical approach, covering aspects from the field level down to the microscopic and molecular level:

1. The development of sustainable disease management strategies

In the Pulse Crop Pathology Group we work closely together with the pulse crop breeders to develop resistant cultivars. We also conduct large field experiments to develop disease management strategies for producers, looking at aspects such as the efficacy of fungicides and the best timing of fungicide applications. More detailed studies on the epidemiology of pathogens involve field and growth room studies to determine temperature and moisture requirements for fungal development as a first step to improve disease management.

2. Pathogen population dynamics with particular emphasis on virulence and aggressiveness towards their hosts

We are interested in the dynamics of fungal populations as this influences the durability of resistance (i.e. resistance break-down) as well as the efficacy of disease management strategies. Population studies involve surveys to collect infected plant material, and large scale pathogenicity testing of recovered isolates on sets of varieties and germplasm with known disease reaction, and often molecular characterization of these isolates. Research in this area also looks at features of particular populations such as sexual recombination, mating type distribution and the genetics underlying mating.

3. The biology of pathogens and host-pathogen interactions

Another focus of the program is the study of host-pathogen interactions at the microscopic and molecular level. Here we investigate the invasion strategies of the pathogens on their legume host, and the reaction of the host cells to this invasion. Collaborative research has also been ongoing looking at the molecular interaction between host and pathogen.

People:

  • Cheryl Armstrong-Cho (Research Assistant)
  • Stephanie Boechler (Senior Research Technician)
  • Candace Knihniski (Research Technician)
  • Trung Le (Research Technician)
  • Anthea Cabral (Research Technician)
  • Adrian Cabral (Postdoctoral Fellow)
  • Jennifer Menat (PhD student)
  • Aurélie Cohen-Skali (PhD student)
  • Maryam Rezaey (PhD student)
  • Morgan Mitzel (Summer student/Technical support 2009/2010)
  • Robin Love (Summer student 20009/2010)
  • David Congly (Summer student 2009/2010)
  • Yukiko Tanaka (Summer student 2010)
Projects
2014 to 2017
This is an international project funded by the Global Crop Diversity Trust aimed at evaluating cultivated x wild lentil introgression lines for multiple traits in multiple environments.
2009 to 2013
Ascochyta blight caused by Mycosphaerella pinodes (MP) is the most important pea disease in Canada and most pea growing regions in the world, often causing serious yield losses. Genetic resistance to ascochyta blight accumulated through two decades of breeding reduces disease severity, however, under cool, wet conditions, the resistance is not sufficient to prevent economic losses. Some accessions of Pisum fulvum, a wild relative of field pea, possess a high level of resistance to ascochyta blight. This project was designed to initiate a long-term strategy for enhancement of ascochyta blight resistance in pea using an integrated genetic improvement approach through interspecific hybridization, careful phenotyping and molecular genotyping.
2009
The project will evaluate the effect of growing mixtures of semileafless (cv. CDC Dakota) and leafy (cv. CDC Sonata) field peas on Mycosphaerella blight development, weed suppression, lodging, and yields. The objectives of the project are to identify an optimum ratio of semileafless to leafy peas for organic production, and to investigate the effect of different pea canopy environments on Mycosphaerella blight development.
2009
Colletotrichum truncatum is a pathogen of several leguminous plant species where it causes a disease called anthracnose. Host specialization, infertility and genetic differentiation among isolates from different hosts have been demonstrated. In the population of C. truncatum from lentil two races were described. Detailed histological studies of the infection process by isolates of both races have revealed quantitative rather than qualitative differences.
2009
Lentil anthracnose is currently the most important lentil disease in Saskatchewan. In a project about to be completed on molecular aspects of this pathogen, we generated an extensive library of genes activated by the anthracnose fungus and by lentil during the infection process. In order to fully benefit from the investment made in this NSERC-CRD, we received one-year funding to confirm the function of a number of genes in the anthracnose fungus, Colletotrichum truncatum, that we have identified and believe to be involved in virulence of the fungus.
2009
Lentil has been grown commercially in western Canada since 1970. Ascochyta lentis, the causal agent of ascochyta blight of lentil is established as one of the most economically important diseases of lentil in Western Canada. To deal with this problem, the widely acceptable genetic improvement strategy is to pyramid resistance genes. Developing closely linked single nucleotide polymorphism (SNP) markers for resistance genes is prerequisite for pyramiding resistance genes. To develop SNP markers, a series of selected recombinant inbred line (RIL) populations derived from resistant sources will be phenotyped under greenhouse conditions (pathogenicity tests) followed by screening available SNP markers across the entire set of RIL populations.
2009
Stemphylium blight caused by the fungal pathogen Stemphylium botryosum is a lentil disease that has become more prominent in Saskatchewan in recent years. The disease is not well studied under our growing conditions, and information is sketchy on optimal conditions for serious outbreaks of stemphylium blight, yield loss and appropriate disease management strategies. The objectives of this 5-year project are to develop a protocol for the mass production of spores (conidia) of Stemphylium botryosum for the purpose of controlled inoculations; to conduct replicated field experiments to determine yield loss through stemphylium blight, using the tunnel system evaluated in the pilot study and the spore inoculum developed under (1); and to evaluate and optimize the use of tunnels and spore inoculation for resistance screening of lentil germplasm to stemphylium blight.