Non-Peer ReviewedSeed exudates have been shown to inhibit the growth of some fungi responsible for seed
rot and seedling blight in canola and mustard. Alternaria brassicae, A. alternata and A.
raphani can all be found on seed of canola and mustard. Previous work indicates deep
infections of Alternaria brassicae and A. raphani significantly reduce seed germination
while A. alternata had no direct effect on germination. The objective of this study is to
determine the effect of seed exudates on seed rot and seedling blight caused by
Rhizoctonia solani, Fusarium spp. and Pythium spp. and determine if seed borne
Alternaria is synergistic to these pathogens by breaking down defensive compounds in
the seed exudates. Seed will be inoculated with Alternaria alternata. to create superficial
surface infection. Susceptibility to Pythium, Fusarium and Rhizoctonia of artificially
infected seed lots and naturally infected seed lots will be tested on water agar, blotter test
and pot test. Seed exudates will also be obtained from seed lots after surface sterilization
and bioassays of the ability of these exudates to support growth of pathogenic fungi and
beneficial bacteria will be assessed