3 research outputs found
Molecular identification of diverse 'Candidatus Phytoplasma' species associated with grapevine decline in Iran
Grapevine (Vitis vinifera) is one of the most important fruits in Iran where the provinces of Qazvin, Lorestan and Markazi are main producers. During 2013â2015, vineyards located in these provinces were surveyed to verify the presence of phytoplasma. The sample collection was based on symptomatology including decline, leaf yellowing and shortening of internodes. Total DNA was extracted from symptomatic and symptomless grapevine samples and used in nested-polymerase chain reaction (PCR) assays with phytoplasma ribosomal primers (P1/Tint followed by R16F2n/R2, R16mF1/mR1, R16(I)F1/R1 or 6R758f/16R1232r). Nested-PCR products were obtained only for symptomatic samples while samples from symptomless plants yielded no PCR products. Restriction fragment length polymorphism (RFLP) analyses with Tru1I, TaqI and Tsp509I and direct sequencing of amplicons followed by phylogenetic analyses indicated the presence of âCandidatus Phytoplasma fraxiniâ, âCa. P. aurantifoliaâ, âCa. P. solaniâ and âCa. P. phoeniciumâ-related strains. In Marzaki province, there âCa. P. aurantifoliaâ strains were mainly detected, while in the other two provinces, all the four âCandidatus speciesâ were identified with the prevalence of âCa. P. solaniâ-related strains. In both provinces in one case, mixed phytoplasma infection was also detected by RFLP analyses. The presence of different phytoplasmas in positive samples indicates great phytosanitary significance due to grapevine economic importance for country. Grapevine phytoplasma infection represents a threat for other crops suggesting grapevine as alternative host species for the phytoplasmas already reported in Iran, while the âCa. P. fraxiniâ is for the first time identified in Iran