Introduction of scab resistance to European breeding programs of winter wheat

Mike Taylor

Abstract

Recent changes in climate and agricultural practices (growing acreage of maize and winter wheat, reduced tillage) increase the danger of a wide scab (fusarium head blight) attack on winter wheat in Europe. Majority of the countries, where the risk of the disease has been low, including Poland, are not well prepared to the imminent epiphytosis. There is no common European system for screening and elimination of grain and flour contaminated with the Fusarium toxins, however some work on proper regulations is in progress. The present attitudes in variety testing and registration usually do not accept some yield decrease in forms showing higher resistance to the fusarium head blight. Fungicides are insufficiently effective, if applied on susceptible varieties or at low level of agrotechny. Therefore, the improvement of scab resistance is a serious challenge for wheat breeders. The European population of wheat varieties is much variable in respect of the resistance. The known sources, as Sumai 3 and Type II, are difficult in routine breeding application; they are usually lost in early generations of crosses, if artificial inoculations are not applied. In Germany, spread of post-harvest remains of maize proved to be an effective inoculation method, which ensures constant and long lasting dissemination of the spores. In comparison with the spraying methods, the inoculation proceeds in a more natural way, from beneath. The prospects of DNA markers use are also optimistic. The co-operation between agricultural institutes and private breeders is expected to prevent the catastrophic epiphytosis, similar to that occurred in North America. There is a demand, addressed to the institutes, for pre-breeding of appropriate wheat forms, which combine short stature with high level of the resistance. There is also a need for research on the relationships between the resistance and flowering biology.