During a survey in a limited area of the Shanxi province in China, phytoplasma symptoms were observed on woody plants such as Chinese scholar tree, apple, grapevine and apricot. The polymerase chain reaction/ restriction fragment length polymorphism (PCR/ RFLP) analyses on the phytoplasma 16S ribosomal gene confirmed that symptomatic samples from all these species were infected by phytoplasmas. The molecular characterization of the pathogen, performed also with sequencing of polymerase chain reaction amplified 16S rDNA, showed that the phytoplasmas detected in all plant species tested are closely related with stolbur, but two samples from a Chinese scholar tree were infected with phytoplasmas related to ÔCan-didatus Phytoplasma japonicumÕ. The presence of RFLP polymorphism was found in the 16S rDNA amplicons with three of the six enzymes employed in the majority of phytoplasma strains studied.

Jujube (Zizyphus jujuba Mill.) witches' broom (JWB) is the most important disease in the areas of jujube cultivation in China, where it occurs every year. Micropropagated shoots of the three most important cultivars (`Lizao', `Junzao', and `Muzao') in the National Jujube Gene Pool, collected at the Pomology Institute of Shanxi province, were tested for the presence of phytoplasmas. Phytoplasma ribosomal (16Sr) general and specific primer pairs were used in direct or nested polymerase chain reaction (PCR). Positive results were obtained only from symptomatic micropropagated samples of `Lizao' and from phytoplasma controls. Restriction fragment length polymorphism (RFLP) analyses of PCR products with several restriction enzymes revealed that the phytoplasmas infecting the symptomatic plants belong to the 16SrRNA group V subgroup B. The positive correlation between symptoms and the presence of phytoplasmas was verified in tissue culture. Samples from apparently healthy shoots of `Junzao', `Muzao', and `Lizao' were free of phytoplasmas.