Sinapis arvensis L . as a source of viruses — Cauliflower mosaic virus (CaMV) and Turnip mosaic virus (TuMV) infecting oilseed rape

Plants of wild species Sinapis arvensis L . — (wild mustard) with severe mosaic symptoms were established all around different farm crops in Sofia valley and even in the Sofia suburbs in 2006. Two viruses were identified by ELISA method (DAS-ELISA) and by the indicator method. Those were the virus of the genus Caulimovirus , family Caulimoviridae — Cauliflower mosaic virus (CaMV) and a virus of the genus Potyvirus , family Potyviridae — Turnip mosaic virus (TuMV). Both viruses were found in wild mustard plants, often in mixed infection. Turnip yellow mosaic virus (TYMV) wasn’t determined in wild mustard plants. CaMV was identified by the infection of its diagnostic indicator species Brassica oleracea var. botrytis (cv. Snowball) — cauliflower. Besides cauliflower, TuMV was also identified in cabbage — Brassica oleracea var. capitata, cv. Balkan, Chenopodium amaranticolor, Chenopodium quinoa and tobacco plants — Nicotiana rustica and Nicotiana tabacum , cv. Samsun. The economically important crop oilseed rape Brassica narus var. oleifera , hybrid Elvis, was infected by artificial mechanic inoculation with material from diseased wild mustard. Oilseed rape plants responded with local and systemic chlorotic mottling of the leaves. A clearly pronounced mosaic appeared on leaf petioles of the growth. Our hypothesis was that the weed Sinapis arvensis could be a reservoir of TuMV and CaMV infection for oilseed rape under natural conditions, if the viruses are transferred from wild mustard to oilseed rape with aphids