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Poster: Biology & Disease Mgmt: Oomycetes


Development of a split-root technique for canola (Brassica napus L.)
G. BRUCE (1), J. Robson (2), M. McDonald (2) (1) Agriculture and Agri-Food Canada, Canada; (2) University of Guelph, Canada

Canola (Brassica napus) is an important oilseed crop in Canada. A split-root system was developed for studies of host-pathogen interaction with root pathogens. Canola seed was germinated on moistened filter paper within pouches. After 7 days, the root tip of each seedling was clipped back to stimulate secondary branching. Each seedling was then carefully planted into soilless mix and allowed to grow for 18 days. When uprooted, each seedling had a pair of secondary roots. One root of each pair was then potted into each side of a specially modified plant pot for subsequent growth and assessment. The modified pots were created by placing two small plastic bags filled with potting mix into a square pot to create two equal but independent sections of soil per pot. A bamboo support was inserted between the bags. The roots were placed into each bag and covered with soil. The young seedling was loosely tied to the support, then sand was added to cover the soil and support the seedling. This resulted in almost 100% survival of the treated seedlings. As an initial proof of concept, seedling roots on one side of each pot were inoculated with resting spores of Plasmodiophora brassicae 7 days after potting and visually assessed for clubroot symptoms at 42 days after inoculation. Clubroot symptoms developed on the inoculated side but not on the control.