Archivio Journal of Plant Pathology

Abstract:

In accordance with the mandatory control of Flavescence dorée (FD) in Italy, a monitoring programme for the presence of the phytoplasma agent of this disease and its vector Scaphoideus titanus Ball. was initiated in Apulia (southern Italy) since 2005. Surveys were carried out annually from June to October and, whenever observed, vines with yellows-like symptoms were tested by nested PCR. For vector catching, sticky traps were placed in a few vineyards and/or nurseries in each of the six Apulian provinces and replaced every two weeks, during the whole insect fly period (mid-June to late September). In 2013, 19 adults of a leafhopper with the morphological traits of S. titanus, as determined using the Douglas and Barnett (1976) key, were captured for the first time in Apulia, on traps exposed from mid August to mid September. The collected specimens were brought to the laboratory and 17 of them were tested individually by nested PCR for the presence of phytoplasmas. The insects were individually ground in CTAB-based buffer (Marzachì et al., 1998), aliquots (2 μl) of the recovered total nucleic acid were subjected to nested PCR using two pairs of generic primers (P1⁄P7, R16F2n⁄R16R2) that amplify phytoplasma 16S rDNA (Gundersen and Lee, 1996). No positive amplifications were obtained. The few vines with yellows-like symptoms present in some vineyards were PCR-positive but, after sequencing of their amplicons, proved to be infected by Candidatus Phytoplasma solani, the agent of Bois noir. Whereas Bois noir is known to occur in Apulia, though sporadically, S. titanus represents a new finding and a threatening one for the well-being of the local viticultural industry.