摘要 : During the last years in the vineyards of South Tyrol (Northern Italy) an increased incidence of grapevine yellows has been observed. Grapevine yellows can be induced by several different phytoplasma strains, the most important in... 展开 During the last years in the vineyards of South Tyrol (Northern Italy) an increased incidence of grapevine yellows has been observed. Grapevine yellows can be induced by several different phytoplasma strains, the most important in Europe being Flavenscence doree (16SrV or Elm yellows group) and Bois noir (BN; 16SrXII-A or Stolbur group) (Lee et al. 1998). Both phytoplasmas are present in the northern part of Italy and in some vine-growing areas they occur simultaneously (Bianco et al. 2002). Although the two diseases considerably differ in their epidemiology and thus require different phytosanitary measures, they can not be distinguished on behalf of the symptoms they induce. For this reason, in South Tyrol a continuous monitoring program has been carried out since summer 2002. In the course of this program vines with yellows symptoms were tested by a nested PCR-RFLP procedure in order to determine the phytoplasma involved (Pasquini et al. 2001, Maixner et al. 1995). So far, in South Tyrol primarily BN was identified, which is transmitted to grapevine occasionally by the polyphagous Cixiid planthopper Hyalesthes obsoletus from vineyard weeds (Weber and Maixner 1998, Alma et al. 2002, Sforza et al. 1998). Recently, the existence of three different sub-types of BN was reported, which can not only be distinguished by molecular traits, but also by their association with different host plant species of the insect vector H. obsoletus (Langer and Maixner 2004). The objective of the present study was to identify the BN-types infecting grapevine in South Tyrol in order to assess the possible reservoirs of this dangerous grapevine disease. By analysing samples collected over a 4-year period it was even possible to gain insight into the stability of distribution patterns over time of the BN-types in the investigated grapevine-growing region. 收起