Overdracht van het aardappelspindelknolviroïde van de sierteelt naar tomaat en aardappel - epidemiologie, risico-analyse en inactivatiemethoden

Potato spindle tuber viroid (PSTVd) is infectious un-encapsidated, small, circular, single-stranded RNA, capable of autonomous replication when inoculated into a host plant. The host range of this pathogen is thought to be relatively narrow. The primary hosts are potato and tomato, yet a number of ornamental Solanaceae can also be infected by PSTVd. A major problem is that the presence of the viroid in those ornamentals remains unnoticed, since no symptom development occurs. Recent surveys show that PSTVd and other related (pospi)viroids are quite commonly found in Solanum jasminoides, Lycianthes rantonnetii and Brugmansia suaveolens. The viroid has been given a quarantine status because of a realistic risk for tomato and potato on which PSTVd does cause important economic damage due to serious growth reductions and malformation of plants and tubers.
The main objectives of the current study is to provide new knowledge of the epidemiology, the transmission risk from ornamental plants to tomato and potato cultures, and the control of PSTVd and other pospiviroids. To address these challenges the following activities were carried out: evaluation of the pathogenicity of a series of Belgian pospiviroid isolates, evaluation of the sensitivity of the most common tomato and potato cultivars against PSTVd, assessment of several controlled transmission experiments (pollen, insects, transmission through root and leaf contact and via irrigation waters, the importance of solanaceous weeds in PSTVd transmission), and chemical and physical inactivation tests. Together with the data of parallel studies on origin, status and molecular characterization of the most important pospiviroids in solanaceous crops (PSTVd, CEVd, CLVd and TCDVd), control strategies can be proposed to avoid further spreading of this quarantine pathogen.

Trefwoorden:viroïden, overdrachtsrisico