Restriction Fragment Length Polymorphism Analyses and Dot Hybridizations Distinguish Mycoplasmalike Organisms Associated withFlavescence Doreeand Southern European Grapevine Yellows Disease in Italy

Biotinylated cloned DNA probes were employed in dot hybridizations and restriction fragment length polymorphism (RFLP) analyses to compare mycoplasmalike organisms (MLOs) associated with two grapevine yellows diseases (strain FDU of flavescence doree MLO from northern Italy and strain FDB of southern European grapevine yellows MLO from southern Italy) and Italian periwinkle virescence disease (MLO strain G from northern Italy). Results from dot hybridizations using six probes containing cloned DNA of MLO strain FDU, of MLO strain G, or of American aster yellows MLO strain AY1, revealed that FDU and FDB shared some regions of DNA sequence homology with one another as well as with MLO strains G and AY1, but all four MLOs were mutually distinguished [...]