Threat of tamarisk phytoplasmas in man-made tamarisk forest for agricultural crops and natural resources plants in Iran

Over the past two decades, symptoms of tamarisk witches’ broom, yellowing, and little leaf were observed with extensive distribution up to 100% in some areas in man-made tamarisk forest in rural deserts of central regions of Iran in Chah Afzal (Yazd province). Using direct and nested polymerase chain reaction on the phytoplasma ribosomal and non-ribosomal genes followed by RFLP and phylogenetic analyses revealed the presence of ‘Candidatus Phytoplasma asteris’ (16SrI-B subgroup), ‘Ca. P. australasiae=australasiaticum’ (16SrII-D subgroup), and ‘Ca. P. trifolii’ (16SrVI-A subgroup). Based on the results, tamarisk represent a relevant source of infection for the agricultural crops and natural resources plants. Since phytoplasma strains detected on the tamarisk trees are similar to important phytoplasma diseases on different plant species in this area, it is possible that tamarisk trees have an important role in the epidemiology of phytoplasma disease and cause great damages. Threat of tamarisk witches’ broom phytoplasma diseases in man-made tamarisk forest for agricultural crops and natural resources plants is serious and management of the disease at the earliest opportunity is recommended.