PARTIAL BIOLOGICAL AND MOLECULAR CHARACTERIZATION OF PHYTOPLASMAS ASSOCIATED WITH GRAPEVINE YELLOWS IN FARS AND LORESTAN PROVINCES OF IRAN*

Grapevine yellows (GY)-like symptoms were found widespread in vineyards of Fars and Lorestan provinces in Iran. To study the etiology of the diseases, cuttings from yellows affected vines were planted in pots and symptomatic vines developed from cuttings were used as the source of yellows agent. Agents of grapevine yellows from Fars (FGY) an Lorestan (LGY) were transmitted from symptomatic young grapevines to periwinkle via dodder inoculation and from periwinkle to periwinkle by grafting. Phytoplasmas were detected in symptomatic periwinkles by direct PCR using P1/P7 primer pair and in12 out of 20 symptomatic field vines, all symptomatic vines developed from cuttings and all inoculated periwinkles by nested PCR using P1/P7 and R16F2n/R16R2 universal primer pairs. Actual and virtual restriction fragment length polymorphism (RFLP) of nested PCR products (1.2 kbp), sequence homology and phylogenetic analysis of full length 16S rDNA classified FGY and LGY phytoplasmas in the 16SrXII-A. Comparison of virtual RFLP patterns indicated that FGY and LGY phytoplasmas are genetically different from the agent of grapevine declining disease previously reported from northeast of Iran as a stolbur related phytoplasma. This is the first report of GY disease in western and southern Iran. Presence of GY in widely separated regions in Iran indicates a long history for the disease in this country.