XIVth International Symposium on Fruit Tree Virus Diseases
Several papers presented at this symposium, of which· the proceedings are published in ACTA Horticulturae n° 235, are of interest to EPPO (authors' names indicated in brackets):
- the presence of the A2 pests apricot chlorotic leafroll MLO (in peach, apricot, and Prunus salicina), and of apple proliferation MLO, is confirmed in Greece (Syrgianidis);
- apple proliferation MLO (A2 list) has been shown in FRG to be vectored by Fieberella florii (Stal) (Krczal et al.);
- a new apple MLO is described from Washington State (US) - apple decline MLO (Parish);
- tomato ringspot nepovirus (A2 list) has been found in prune cv. Agen on P. cerasifera rootstock in Chile. Its known vector, Xiphinema americanum (A2 list) is common in Chilean prune orchards (Auger);
- high specific-activity cRNA probes are available now for tomato ringspot nepovirus (Hadidi & Hammond) and plum pox potyvirus (Varveri et al.);
- peach latent mosaic is caused by a viroid (see also EPPO Reporting Service· n° 506/03);
- 150 apricot cultivars have been screened for susceptibility to apricot chlorotic leafroll MLO (A2 list) and great variability found (Audergon et al.);
- plum pox potyvirus is still the subject of much research. Monoclonal antibodies have been developed against it and used in ISEM (Himmler et al.). Epidemiological studies, assisted by computer models, suggest that the disease can be contained in the long term on apricot in France, as long as orchards are regularly surveyed and infected trees destroyed (Morvan); in Italy (Refatti et al.), an attempt is being made to eradicate the disease from the Sarca Valley (Trento province). Resistance and susceptibility are widely studied: in nectarine in Greece (Syrgianidis & Mainon); in apricot in Greece (Karayiannis); in apricot in France (Dosba et al.); in plum in Yugoslavia (Rankovic & Paunovic). Finally, a round-table discussion (Dosba) developed future policy for the ISHS plum pox group.
Sources
Acta Horticulturae.