Corn with Symptoms of Reddening: New Host of Stolbur Phytoplasma.

Recurrent epiphytotic outbreaks of a disease of uncertain etiology known as reddening of corn (Zea mays) have occurred in some areas of Serbia during the last 50 years. Affected plants show early and abnormal ripening, dry precociously, and have poor, shriveled grains. Using molecular tools, phytoplasmas were detected in diseased plants and their identity was subsequently deduced as a subgroup 16SrXII-A strain by a variety of supporting assays involving restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction (PCR)-amplified 16S rDNA and tuf gene sequences, selective amplification of phytoplasma DNA using primer pair G35p/m, similarity of 16-23S intergenic spacer region (SR) sequences, and similarity and phylogenetic analysis of 16S rDNA gene sequences. Presence of stolbur phytoplasmas in corn with reddening symptoms is a new finding not only for Serbia: it is the first report of stolbur phytoplasma in this species worldwide.