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Las amarilleces de la vid en Chile actualmente están asociadas a fitoplasmas pertenecientes a los grupos ribosomales 16SrI-B, 16SrI-C (ambos del genero ‘Candidatus Phytoplasma asteris’, 16SrVII-A (‘Ca. P. fraxini’) y 16SrXII-A (stolbur). La presencia de estos patógenos en las plantas depende de la propagación de material vegetal infectado y la diseminación natural ocurre por medio de diferentes especies de insectos vectores auquenorrincos (langostinos). Con la finalidad de averiguar la presencia de langostinos en los viñedos chilenos y determinar su rol en la transmisión de fitoplasmas, se ha procedido a la captura de individuos que han sido caracterizados y analizados para detectar fitoplasmas. Se ha podido así recolectar insectos pertenecientes a la subfamilia Delthocephalinae (familia Cicadellidae) y a las familias Cixiidae y Delphacidae, todos potenciales vectores de fitoplasmas. Varios insectos han resultados positivos a fitoplasmas y el 16SrXII-A (madera negra) se encontró en individuos que, según una primera caracterización, pertenecerían a los géneros Macrosteles ó Exitianus.

Detection and identification of phytoplasmas associated with Chilean grapevines was performed. Symptomatic and/or asymptomatic grapevine plants were sampled and tested by nested PCR, that allows the detection of phytoplasmas in 30 out of 91 samples. Identification by RFLP analyses assigned the detected phytoplasmas to 16SrI-B, 16SrI-C, 16SrVII-A and 16SrXII-A ribosomal subgroups. Cloning and sequencing selected isolates allow the detection of genetic variability in 16SrXII-A Chilean strains. The finding of 16SrVII-A phytoplasmas is new for grapevine, while appear to be detected in different host species. Flavescence doree was not detected in Chilean grapevines. Infection with more than one type of phytoplasma is not uncommon in Chilean grapevines. Mixed infections between phytoplasmas and viruses frequently occur, that difficult the visual diagnosis. There is no evidence of epidemic spreading of yellows symptoms in the surveyed vineyards, nevertheless, future danger of 16SrXII-A epidemic spreading is not totally excluded. Survey to verify the presence and identity of insect vector or potential vector and also possible herbaceous weed hosts plants, acting as reservoir of phytoplasmas, are in progress.

Nel periodo 2000-2003 nelle aree più intensamente vitate della regione Abruzzo è stata effettuata un'indagine tesa ad accertare la presenza di Flavescenza dorata e del suo vettore Scaphoideus titanus. I risultati delle analisi molecolari hanno escluso la presenza del fitoplasma della flavescenza dorata (FD) mentre hanno accertato la presenza dei fitoplasmi del legno nero (BN) e del “clover phyllody”. Contemporaneamente l'identificazione delle cicaline rinvenute nei siti indagati ha escluso la presenza di Scaphoideus titanus, ma ha accertato quella di altre cicaline alcune delle quali note in letteratura come vettrici di fitoplasmi: Hyalesthes obsoletus, Macrosteles spp e Oliarius spp..