Identification and eradication of potato spindle tuber viroid in dahlia in the Netherlands

In 2013, potato spindle tuber viroid (PSTVd) was identified in 17 lots of seven dahlia cultivars at a single company in the Netherlands. Analysis of the genotypes showed highest identities with a PSTVd genome from dahlias in Japan. The dahlia isolate could be transferred experimentally to tomato and potato. In tomato this resulted in mild chlorosis and stunting; in potato no symptoms appeared, nor in aerial parts, nor in tubers. The infections in dahlias were eradicated by destroying all infected lots at the infested company. No infections were found in lots of the same cultivars grown by other companies. Moreover, PSTVd was not detected in any of the lots of three other companies that had bought dahlia planting material of the infested company. In 2014, PSTVd was not found in a survey including all cultivars in which PSTVd had been identified in 2013. Therefore, it was concluded that PSTVd had been eradicated in dahlias in the Netherlands.