Resistance of cereals to soil-borne viruses

摘要

Soil-borne viruses, belonging to the genera Furovirus and Bymovirus, are serious pathogens of winter cereals, transmitted by root-inhabiting fungal-like plasmodiophorid Polymyxa graminis. The vector is widely spread through in Asia, North America andEurope. In Europe there are two main cereal diseases caused by soil-borne viruses: barley yellow mosaic and soil-borne cereal mosaic. Plant protection against this kind of viruses is based exclusively on the cultivation of resistant or tolerant cultivars, as chemical control remains ineffective regarding the biological properties of the vector and unacceptable from the ecological point of view.Symptoms of barley yellow mosaic are caused by two closely related viruses: Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV), which infect only winter barley. Genetic studies led to the identification of sixteen genes carrying theresistance feature to the barley yellow mosaic viruses in barley.Soil-borne cereal mosaic virus (SBCMV), the causal agent of soil-borne cereal mosaic, can infect different cereal species, including wheat, triticale, rye and barley. Investigations on the resistance of wheat to SBCMV revealed that diverse mechanisms areinvolved in the reaction of plants and final effect of infection is dependent on many factors including climatic conditions.