Are rapeseed varieties resistant to Turnip yellows virus (TuYV) the solution against viruses transmitted by aphids?
Abstract: Three viral species (i.e. Turnip yellows virus (TuYV), Turnip mosaic virus (TuMV) and Cauliflower mosaic virus (CaMV)) were detected in winter oilseed rape crops in France in the early 1990’s. These viruses are transmitted by several aphid species including Myzus persicae which is reported to be present at a rate up to 60% on average in rapeseed fields in production areas in France. TuYV is the most prevalent virus reported so far in oilseed rape. Neonicotinoids (foliar spraying) is the last efficient insecticide family against Myzus persicae that can be used in rapeseed in autumn in France to protect this crop against vector-borne viral diseases. With the ban of this chemical family by the French authorities scheduled in September 2018, oilseed rape varieties resistant to viruses are of great interest. The first TuYV-resistant oilseed rape variety (cv. Architect) was registered in France in 2016. Trials carried out with different varieties including cv. Architect showed that infection rate and viral accumulation in infected plants were lower in the resistant varieties than in the susceptible control cv. DK Exception. The partial resistant phenotype of these varieties was associated to a yield gain when trials were under high viral pressure, while in trials with low virus pressure no yield gain was associated with the TuYV-resistance. Unfortunately, varieties resistant to TuYV are not resistant to the other two viruses (CaMV and TYMV) reported in oilseed rape crops which can occasionally strongly affect rapeseed production.