Tobacco ringspot virus detected on Phlox subulata in the Netherlands
During a regular survey, Tobacco ringspot virus (Nepovirus, TRSV - EPPO A2 List) was found in the Netherlands on Phlox subulata. In February 2010, TRSV was detected (DAS-ELISA, biological tests) in asymptomatic samples of P. subulata cv. ‘Alexander’s Surprise’ in 1 production site (glasshouse) in Boskoop. Planting material of this cultivar had been delivered by a Dutch nursery located in Voorhout. 11 samples were taken from the nuclear stock of cv. ‘Alexander’s Surprise’ and were all found to be infected by TRSV. According to delivery notes, this nursery had not exported cuttings of this cultivar to other countries but only to 11 Dutch production sites where investigations were conducted. Later in 2010, another finding was made in a different cultivar, P. subulata cv. ‘Temiskaming’ in another location. The infected lot had been produced from nuclear stock originally obtained from another nursery. This new finding indicates that TRSV has probably occurred on some cultivars of P. subulata for a longer period in the Netherlands because this nuclear stock material has been used for many years.
The main vector of TRSV is the nematode Xiphinema americanum which does not occur in the Netherlands, vegetative propagation is thus considered to be the most probable pathway for spreading TSRV in the Netherlands. Eradication measures are being taken in all infested or potentially infested sites. In particular, a compulsory testing protocol will be initiated on propagation material, and all infected lots of nuclear stock plants will be destroyed. Eradication efforts will be targeted at cultivars ‘Alexander’s Surprise’ and ‘Temiskaming’, but depending on the results they may be extended to other Phlox cultivars or other plant genera. It is finally noted that these findings on Phlox are not related to earlier outbreaks of TRSV on Iris and Hemerocallis which have been eradicated (see EPPO RS 2009/033). The pest status of Tobacco ringspot virus in the Netherlands is officially declared as: Transient on Phlox subulata cvs. ‘Alexander’s Surprise’ and ‘Temiskaming’, under eradication.
NPPO of the Netherlands (2010-03, 2010-10).
Website of the Dutch Food and Consumer Product Safety Authority - Pest reports. http://www.vwa.nl/onderwerpen/english/dossier/pest-reporting/pest-reports