Phytoplasmas associated with grapevine yellows disease in Iran: first report of a 'Candidatus Phytoplasma trifolii'-related strain and further finding of a 'Ca. P. solani'-related strain.
Over recent years, grapes (Vitis vinifera) with symptoms similar to grapevine yellows disease (severe yellows and redness, inward curling of leaves and stunting) have been observed in vineyards from different regions of Iran, especially Zanjan province. Therefore, a survey was conducted in 2018 to identify possible phytoplasma agents. A total of 19 samples from symptomatic (16) and asymptomatic (3) plants (cvs. Keshmeshi Qermez and Askari) were collected from vineyards in the Darsajin, Khoramdareh and Zanjan areas in Zanjan province. The causal pathogens were isolated and identified as a Phytoplasma trifolii'-related strain and a P. solani'-related strain based on various molecular analyses. This is thought to be the first report of a P. trifolii'-related strain associated with grapevine yellows disease in Iran.