Iveta Megrelishvili

Iveta Megrelishvili

LEPL Scientific Research Center of Agriculture, Georgia

Flavescencedorée (FD) and Bois noir (BN) are two grapevine yellows diseases (GY), associated with phytoplasmas considered quarantine pests in Georgia.Symptoms of diseases caused by phytoplasmas were observed in Georgian vineyards, showinga wide distribution of grapevine yellows in the Country.

The main goal of the research was to study grapevine yellows phytoplasma diseases in Georgian region of Kakheti (villages Kondoli, Napareuli, Tsinandali) on three international grapevine varieties (Chardonnay, Sauvinion blanc, Tempranillo), and Georgian variety Khikhvifor selection of phytoplasma disease-free grapevine varieties in order to develop plant sanitary system in Georgia. Totally 259 symptomatic and asymptomatic grapevine samples were analyzed using a new triplex real-time PCR assay with TaqMan minor groove binder probes (TaqMan-MGB), and a Double Antibody Sandwich-Enzyme linked Immunosorbent Assay (DAS-ELISA) with commercial complete Kit DAS ELISA Poly/Mono (Biotin) (SEDIAG).

According to triplex real-time PCR TaqMan assay 38 out of 259 tested samples reacted positively, whereas infection was not found in any researched samples by DAS-ELISA, indicating that the latter technique is not suitable for phytoplasma detection.

Phytoplasmas associated with Flavescencedoree(6.3%) and Bois Noir (11.8%) were found in symptomatic plants of the cultivar Chardonnay (6.3% and 11.8% of the examined samples, respectively) and Tempranillo (3.4% and 4.2% of the examined samples, respectively). Symptomatic plants of the cultivar Khikhvi were found infected exclusively by FD phytoplasma (5.1% of the examined samples), while no phytoplasma infection was detected in the cultivars Sauvinion blanc.

Interestingly, result highlighted the first report of Flavescencedoree (FD) phytoplasma in grapevine varieties Chardonnay, Tempranillo, and ‘Khikhvi in Georgia.