Flavescence dorée (FD) phytoplasma is associated with grapevine yellows, a serious threat for wine production in Europe. FD is epidemic in north-western Italy and is transmitted by Scaphoideus titanus Ball, a monovoltine neartic leafhopper, monophagous on grapevine. Following pruning of FD infected branches a high rate of recovery from the disease occur on grapevines, with percentage varying according to different cultivars. The recovered plant remains symptomless if not exposed to new infective vectors. If recovered plants are not suitable for vector acquisition it is possible to rely on recovery as a strategy for disease management instead of eradication of infected plants. To this purpose, acquisition capability of S. titanus, following feeding on recovered grapes was established and compared with that on infected grapevines, considering different varieties (Barbera vs. Nebbiolo) and different moment of the season (early June vs. late August). Sanitary status of source grapes was confirmed by nested PCR. Leafhopper nymphs were caged for one week on chosen grapevine branches, in vineyards located in different viticultural areas of the Piemonte Region. Insects were then collected and maintained in greenhouse for three weeks on healthy grapevines to complete the latent period, subjected to DNA extraction and analyzed in nested PCR to determine phytoplasma presence. S. titanus acquired FD from infected grapevines only, with higher efficiency from Barbera than Nebbiolo and in August than in June. Recovered plants did not represent a source of inoculum for the vector and therefore do not impact on FD spread.
Pattern of Flavescence dorée ("Candidatus Phytoplasma vitis") acquisition by Scaphoideus titanus Ball (Hemiptera Cicadellidae) from recovered and infected grapevines of different cultivars
Galetto L;Bosco D
2013
Abstract
Flavescence dorée (FD) phytoplasma is associated with grapevine yellows, a serious threat for wine production in Europe. FD is epidemic in north-western Italy and is transmitted by Scaphoideus titanus Ball, a monovoltine neartic leafhopper, monophagous on grapevine. Following pruning of FD infected branches a high rate of recovery from the disease occur on grapevines, with percentage varying according to different cultivars. The recovered plant remains symptomless if not exposed to new infective vectors. If recovered plants are not suitable for vector acquisition it is possible to rely on recovery as a strategy for disease management instead of eradication of infected plants. To this purpose, acquisition capability of S. titanus, following feeding on recovered grapes was established and compared with that on infected grapevines, considering different varieties (Barbera vs. Nebbiolo) and different moment of the season (early June vs. late August). Sanitary status of source grapes was confirmed by nested PCR. Leafhopper nymphs were caged for one week on chosen grapevine branches, in vineyards located in different viticultural areas of the Piemonte Region. Insects were then collected and maintained in greenhouse for three weeks on healthy grapevines to complete the latent period, subjected to DNA extraction and analyzed in nested PCR to determine phytoplasma presence. S. titanus acquired FD from infected grapevines only, with higher efficiency from Barbera than Nebbiolo and in August than in June. Recovered plants did not represent a source of inoculum for the vector and therefore do not impact on FD spread.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
