Molecular identification of stolbur phytoplasma associated with red clover dwarf disease symptoms

Abstract

Trifolium pratense plants exhibiting dwarf symptoms without flower abnormalities were frequently observed in the breeding nurseries in North Moravia, Czech Republic. Direct and nested polymerase chain reaction with phytoplasma-specific primers and subsequent restriction fragment length polymorphism analyses of 16S rDNA, as well as sequence analyses of the 16S-23S ribosomal operon, identified phytoplasmas belonging to the ribosomal subgroup 16SrXII-A. Identical analyses of the dnaB gene and the transcription factor tuf gene were used for further differentiation. The primer\enzyme-combination of TufAYf,r\HpaII revealed the grouping of the phytoplasmas into stolbur tuf-type II in all examined samples. Stolbur phytoplasmas have not been reported previously in red clover. © 2009 Blackwell Verlag, Berlin.