Detection of aster yellows group (subgroup 16SrI-B) phytoplasma in oats based on nested PCR and RFLP in Lithuania

Phytoplasma strains were detected in oats (Avena sativa L.) in Lithuania exhibiting disease symptoms of stunting, sterile, deformed and yellow spikes. A phytoplasma-characteristic 1.8 kb and 1.2 kb rDNA PCR products were amplified from DNAs of all diseased but not healthy oat plants tested, using phytoplasma universal primer pairs P1/P7 and R16F2n/R16R2 confirming that symptomatic plants were infected by phytoplasma. Phytoplasma was termed oat stunt (OatSt). Restriction fragment length polymorphism (RFLP) analysis of amplified 16S rDNA indicated that diseased oats were infected by phytoplasma belonging to the group 16SrI (aster yellows, AY, group) and subgroup 16SrI-B. This is the first report of phytoplasma belonging to 16SrI (aster yellows) group and 16SrI-B phytoplasma subgroup identified in oat plants.