New insights on “bois noir” epidemiology in the Chianti Classico area, Tuscany

Bois noir” (BN) is the most widespread disease of the grapevine yellows complex in several countries worldwide. BN is associated with the presence of ‘Candidatus Phytoplasma solani’, transmitted from herbaceous plants to grapevine by polyphagous insect vectors. In the present study, a preliminary investigation on the epidemiology of BN in the Chianti Classico area was carried out in an organic Sangiovese vineyard. ‘Ca. P. solani’ strains identified in symptomatic grapevines and insects were typed through the analysis of the stamp gene nucleotide sequences. Obtained results revealed the presence of 4 stamp sequence variants in grapevines and the exclusive presence of the sequence variant St10 in Reptalus quinquecostatus, the sole insect species found infected by this phytoplasma in the studied vineyard.