engleski

Molecular variability of Potato spindle tuber viroid in ornamental plants in Croatia

Viroids of the genus Pospiviroid are able to induce diseases in a wide range of host plants including important crop species. Although occasional disease outbreaks of Potato spindle tuber viroid (PSTVd) and closely related pospiviroids have been reported in potato and tomato, recent studies found an increase in number of latent infections in ornamental solanaceous species. In order to verify the presence of PSTVd in Croatia, a survey was conducted between 2009 and 2013. A total of 222 samples belonging to five ornamental species and two solanaceous crops were analyzed. Samples were collected from nurseries and consisted of eight randomly upper leaves taken from individual plants. Total RNA was extracted from symptomless leaf tissue and utilized as template in one-step reverse transcription - polymerase chain reaction (RT-PCR). The full length genome, corresponding to the viroid size (360 bp) was obtained using the PSTVd-32/ PSTVd-33 primer pair. Eleven plants belonging to two different species (Solanum jasminodes and Lycianthes rantonnetii) were found positive in this assay. The amplicons were extracted from agarose gel, cloned and sequenced. The Basic Local Alignment Search Tool (BLAST) confirmed their respective viroid identity and phylogentic relationships were evaluated using neighbour joining (NJ) implemented through MEGA 6.0. Although infected ornamentals do not show obvious symptoms of viroid infection, they pose a persistent danger of spreading infection by vegetative propagation material. Therefore, it is extremely important to use certified seed, apply sanitary measures and conduct regular inspection monitoring to prevent the spread this quarantine pathogen in the future.

Lycianthes rantonnetii ; Potato spindle tuber viroid ; RT-PCR ; Solanum jasminodes

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