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Poster: Biology & Disease Mgmt: Genetics of Resistance


Resistance to Claviceps purpurea (Fr.) Tul. in the winter wheat lines “Robigus” and “Solstice”.
J. MENZIES (1), A. Gordon (2), D. O'Sullivan (3) (1) Agriculture and Agri-Food Canada, Canada; (2) National Institute of Agricultural Botany, United Kingdom; (3) University of Reading, United Kingdom

Ergot, caused by Claviceps purpurea, is an important disease of cereals which can result in extensive financial losses to producers because of the presence of sclerotia containing toxic alkaloids in the grain. The severity of ergot in Canada and parts of Europe has increased over the past 20 years, and the development of wheat lines with resistance is being explored. The objective of this work was to determine if the winter wheat varieties “Robigus” and “Solstice” possess physiologic resistance to C. purpurea. Two winter wheat lines (“Robigus” and “Solstice”), two spring wheat lines ((“Paragon” and “Cadillac”) and one durum wheat line (“Avonlea”) were inoculated with 5 Canadian and 4 UK isolates of C. purpurea. Nine spikes per wheat line were needle inoculated prior to anthesis for each pathogen isolate using a conidial suspension. Each spike was assessed for honeydew production 14 days after inoculation using a scale of 1 to 4; 1 = no honeydew to 4 = large drops running down the spike. The weight and number of sclerotia per spike were determined at plant maturity. “Robigus” had significantly lower honeydew production than “Solstice”, which had lower production than the other three lines. “Robigus” and “Solstice” also had significantly lower sclerotial weight and number per spike than the other three lines. “Robigus” and “Solstice” showed resistance to infection by C. purpurea compared to the other three wheat lines.