Molecular detection of prokaryotes in apricot showing decline and leaf scorch symptoms in Iran.

During field surveys in 2015 and early spring 2016 in orchards of Mahvelat and Khaf regions of Razavi-Khorassan province in Iran a severe apricot decline was observed in the 22 to 27% of the cultivars Shahroodi and Lasjerdi. Diseased trees exhibit generalized yellows, upward curling and scorch of the leaves, premature and small leaf, and often fruit dropping, together with growth reduction and premature leaf discoloration. Molecular detection carried out on extracted nucleic acid with PCR and pathogen specific primers allow to verify the presence of phytoplasmas belonging to ribosomal groups 16SrXII and 16SrI in mixed infection, and in some samples of bands referable to the presence of Xylella fastidiosa. The first detection of these pathogens in the same species represents a big threat not only for the Iranian apricot cultivations, but also for agriculture in general, considering that all the detected prokaryotes are infecting a high number of plant species.