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Plant disease is the result of host-microbe interaction.
Based on the gene- for-gene theory, plant resistance in a plant depends on the
specificity and virulence of the pathogen and the resistance genes in the
host plant. My research goal is to understand the resistance mechanism
toward Septoria Leaf Blotch diseases in cereals.
My lab has been using RFLP analysis and PCR amplification of DNA to study genetic
variation and to differentiate the fungal pathogens, Stagonospora spp. The
molecular methods can complement the traditional method and be used for
species identification. Less aggressive Stagonospora nodorum isolates were biologically
characterized in the lab. The isolates were less infectious towards
wheat, triticales and rye, and with "+" mating type, and had
the same ITS sequence as the highly aggressive ones. Genetically, the less
aggressive isolates were different from the highly aggressive pathogens.
These results imply the possible identification of fungal virulence
element(s) by sexual crossings and segregation.
Tagging of the resistance gene(s) in barley against Stagonospora nodorum is
in progress. Wheat genes encoding ACC synthase, methyl transferase and
glutathione-S-transferase, which are related to tissue senescence, have been
identified and their involvement in plant disease resistance is under
study.
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