Institute of Soil Science, Agro Technologies and Plant Pprotection, Nikola Pushkarov, 7 Shosse Bankya, 1331 Sofia, Bulgaria
Abstract. Many viruses infect pepper in Bulgaria including Cucumber mosaic virus (CMV), Pepper mild mottle virus (PMMV), Tobacco mosaic virus (TMV), Tomato spotted wilt virus (TSWV) and Potato virus Y (PVY). These viruses can infect either singly or in combination. CMV has been described as one of the five most important viruses infecting vegetable species worldwide. The virus causes severe mosaic symptoms, stunting, various types of necrosis and leaf deformation. Fruits are often malformed and necrotic lesions are common, thereby drastically reducing marketable yield. Control of CMV can be achieved by planting of resistant crops, but resistance in many crop species is often not available to a broad range of CMV strains. Developing and improving resistant lines by conventional breeding is very difficult since there are no CMV-resistant lines on the market. From the different treatment schemes best results were obtained from pepper plants treated with 5 mM BION and the combination BION+EXIN three days before CMV inoculation. For the plants treated after virus inoculation the best scheme is the combination BION+EXIN. Reduction of the virus symptoms is not always associated with its reduction of the virus titer. Different cultivars expressed different immune reactions to these plant viruses according to the genomic characteristics of the plant cultivar and the virus. Treatment with these SAR elicitors reduced losses from the CMV infection to almost zero.