Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2005
Publication Date: 11/1/2005
Citation: Valiunas, D., Staniulis, J., Davis, R.E. 2006. 'Candidatus Phytoplasma fragariae', a new phytoplasma taxon discovered in yellows diseased strawberry, fragaria x ananassa. International Journal of Systematic and Evolutionary Microbiology. 56:277-281.
Interpretive Summary: Phytoplasmas are small, wall-less bacteria that cause economically important diseases in many plant species around the world. To prevent the spread of a phytoplasma into new geographical regions, there is need to distinguish it from other phytoplasmas. We have investigated strawberry yellows, a new disease that is affecting cultivated strawberry in Lithuania. Results from our DNA analyses showed that this phytoplasma differs from all previously named phytoplasma species. In this paper, we present the results of these analyses, including unique gene sequences useful for detection and identification of the strawberry yellows phytoplasma, and we describe the phytoplasma as a new species, ‘Candidatus Phytoplasma fragariae’. This study will be of interest to scientists, plant disease diagnostics centers, and diagnostics companies involved in work to reduce the spread and adverse impacts of plant diseases, as well as government agencies involved regulating the international movement of plant materials.
Technical Abstract: Symptoms of general stunting and yellowing of leaves were observed in diseased cultivated strawberry (Fragaria x ananassa Duch.) in Lithuania. Analysis of 16S ribosomal (r) DNA amplified in the polymerase chain reaction (PCR) indicated that the symptoms were associated with infection by a phytoplasma, designated strawberry yellows (StrawY) phytoplasma. Phylogenetic analysis of 16S rDNA sequences indicated that StrawY phytoplasma, ‘Candidatus Phytoplasma australiense’, ‘Ca. P. asteris’, stolbur phytoplasma, and ‘Ca. P. japonicum’ shared a common ancestor but were mutually distinct. Nucleotide sequence alignments revealed that StrawY phytoplasma shared 97•4 % or less identity of a 1•3 kb 16S rDNA fragment with previously described ‘Candidatus Phytoplasma’ species. These results, in addition to natural host and geographical occurrence, support recognition of StrawY phytoplasma as representative of a novel taxon, ‘Candidatus Phytoplasma fragariae’.