Molecular detection, classification and phylogenetic analysis of subgroup 16SrI-C phytoplasmas detected in diseased Poa and Festuca in Lithuania

Abstract

Phytoplasma strains were detected in two grass species, Poa pratensis L. (common meadow grass) and Festuca arundinacea Schreb. (tall fescue), exhibiting yellows disease symptoms in Lithuania. Analysis of amplified 16S rDNAs revealed that the phytoplasmas associated with these diseases, designated as poa stunt (PoaS) and festuca yellows (FesY), respectively, were ‘Candidatus Phytoplasma asteris’-related strains belonging to group 16SrI (aster yellows phytoplasma group) subgroup 16SrI-C (I-C, clover phyllody phytoplasma subgroup). Together with other data, the results strengthen the concept that subgroup I-C phytoplasma strains have a broad pathogenic potential. It is possible that P. pratensis and F. arundinacea, previously undescribed as phytoplasma hosts, play a role in the epidemiology of phytoplasmal diseases affecting cereal grasses like oat and rye in the region. The insect vectors of subgroup 16SrI-C phytoplasma strains in Lithuania and neighboring countries remain unknown, emphasizing the need for future investigations to understand how these phytoplasmas spread in the Baltic region. Keywords: Mollicutes, clover phyllody, PCR, RFLP, phylogeny, PoaS, FesY