Sources of off-types in pedigreed seed of common spring wheat

This survey reports on the number and type of off types observed in purity of variety small-scale field plots of common spring wheat. Generally, contamination levels were <0.02%, out-crossing rates using awnedness as an indicator were <0.002%, gliadin fingerprint variants were <0.01%, and mechanical admixtures were <0.01%. Contamination levels were rarely above acceptable impurity tolerances, indicating that the Canadian pedigreed seed certification system, as prescribed by the Canadian Seed Growers' Association, currently recommends operating procedures that achieve high seed purity.