A survey of viruses’ occurrence in Polish and imported tulip bulbs

Virus-infected tulip bulbs produce flowers with virus symptoms what makes cut flowers unmarketable. The aim of the work was to check frequency of virus presence in bulbs intended for forcing and originating both from the Polish farms and imported from The Netherlands. The tests were carried out on four tulip cultivars– ‘Hermitage’, ‘Pretty Woman’, ‘Purple Prince’ and ‘Strong Gold’ during four forcing seasons between 2010 and 2013. Bulb samples were tested by DAS-ELISA using antibodies specific for following viruses: Tulip breaking, TBV, Tobacco necrosis, TNV, Lily symptomless, LSV, Cucumber mosaic, CMV, Tobacco rattle, TRV (J and F strains) and Tulip X, TVX. The most frequently detected virus, both in Polish and Dutch bulbs, was TBV (138 positive results among 1,360 tested samples, during four seasons, what means approx. 10 percent). However, TBV was detected predominantly in bulbs originating from the Polish plantations. Other viruses were detected sporadically. Our results lead to the conclusion that the selection done during tulip vegetation on the examinated Polish farms and removal of diseased plants was not effective and chemical protection against aphids as TBV vectors may be insufficient. Consequently, many tulip bulb lots taken from the examined Polish plantations cannot meet the high quality level of Dutch bulbs, in particular in the case of TBV occurrence.