Induction of systemic disease resistance in carrot roots by pre-inoculation with storage pathogens

The possibility of inducing systemic resistance to gray mold rot in carrot was investigated with roots stored at 1-degrees-C and pre-inoculated with storage pathogens. Pre-inoculating the bottom half of the roots with mycelial plugs of Botrytis cinerea or Sclerotinia sclerotiorum decreased the amount of gray mold rot when the carrots were subsequently challenged with B. cinerea near the crown 25 days later. The effectiveness of the resistance-inducing lesions in providing protection was related to the amount of inoculum used for pre-inoculation. These results indicate that the mechanisms of induced systemic resistance can be turned on at low temperatures and thus could be used for increasing disease resistance in cold-stored carrots. This is the first report on induced systemic disease resistance in the Apiaceae.