During 2013–2015 surveys in Fars, Lorestan and Yazd provinces (Iran), a field bindweed witches’ broom (FBWB) disease was observed. The main symptoms were reduction of leaves size, yellowing, internode shortening, witches’ broom and stunting. The agent of FBWB was dodder transmitted to periwinkle plants inducing phytoplasma-type symptoms. Amplifications of nearly 1.8 and 1.2 kbp were, respectively, obtained from 15 symptomatic bindweed plants and 28 symptomatic dodder-inoculated periwinkles. Virtual RFLP analyses showed that the phytoplasma detected belonged to 16SrXII-A subgroup, and it was the same in all the samples examined; phylogenetic analyses confirmed it as a ‘Candidatus Phytoplasma solani’-related strain. This is the first report of 16SrXII-A phytoplasmas presence in bindweed plants showing witches’ broom symptoms in Fars, Lorestan and Yazd provinces. As a perennial widespread weed, it may act as a 16SrXII-A phytoplasma source for alfalfa, grapevine, Sophora alopecuroides, tomato, hemp and Japanese spindle reported diseases in these Iranian provinces.

Effects of dietary inclusion of commercial toxin binders and prebiotics on performance and immune responses of broiler chicks fed aflatoxin-contaminated diets

Tamarisk witches’ broom, yellowing, and little leaf symptoms were observed during 2018–2023 surveys of rural deserts in central regions of Iran with the highest disease incidence up to 72% in Chah Afzal (Yazd province). A verification of the presence and identity of phytoplasmas associated with these symptoms was then performed. Tamarisk tree branch cuttings obtained from symptomatic plants sprouted up to 90.3% but with 15–25 days’ delay compared to the asymptomatic ones and showed internode shortening and witches’ broom, while the branch cuttings from asymptomatic plants had normal growth and sprouted up to 97.8%. Phytoplasma transmission by dodder bridges to periwinkle did not succeed, while nested polymerase chain reaction on the phytoplasma ribosomal gene followed by RFLP and phylogenetic analyses revealed the presence of ‘Candidatus Phytoplasma asteris’, ‘Ca. P. australasiae=australasiaticum’, and ‘Ca. P. trifolii’ (ribosomal subgroups 16SrI-B, 16SrII-D, and 16SrVI-A, respectively) in the samples from symptomatic plants only. Further amplifications were performed on selected phytoplasma-positive samples on tuf and secA genes, and the produced sequences indicated the presence of mixed phytoplasma infection in some of the samples. In particular, in the tuf gene, a mixed infection of ‘Ca. P. australasiae=australasiaticum’ and ‘Ca. P. trifolii’ was detected, while in the secA gene, the presence of ‘Ca. P. asteris’ or ‘Ca. P. tritici’ strains was identified. The first-time detection of diverse phytoplasma strains in symptomatic T. aphylla suggests that this species represent a relevant source of infection for the agricultural crops and for landscape plants especially when temperature allows insect vector transmission, and therefore, it represents a risk in every environment especially in the frame of climatic changes.