Diversity, distribution, and status of phytoplasma diseases in Iran

In Iran, although phytoplasmas and their associated diseases have been observed in sesame since 1965 as “green flowering of sesame” the agent associated with the disease and its insect vector were reported for the first time in 1992 by electron microscopy, transmission assays, host range, and symptomatology studies of sesame phyllody samples collected from Darab, Fars province. Since then, many phytoplasma diseases have been identified on various plant species in the country. Among them, several new phytoplasma strains and host species have been reported for the first time worldwide. Some of these phytoplasma diseases are very destructive and have a great economic importance. So far, phytoplasma strains enclosed in 12 ribosomal groups have been identified or are being studied across at least 29 plant families. Identified phytoplasma groups are 16SrI, 16SrII, 16SrIII, 16SrVI, 16SrVII, 16SrIX, 16SrX, 16SrXI, 16SrXII, 16SrXIV, 16SXXIX, and 16SrXXX. Among these, the 16SrII is the most important and widespread and lime and alfalfa witches’ broom are examples of destructive and economically important phytoplasma diseases in Iran.