INCIDENCE AND GENETIC DIVERSITY OF PEACH LATENT MOSAIC VIROID ISOLATES IN TURKEY

In 2004 and 2005, 51 peach and 5 nectarine trees from different peach growing areas of the East Mediterranean Region of Turkey were analyzed by RT-PCR for the presence of Peach latent mosaic viroid (PLMVd). Most of the samples were from germplasm collections and did not show specific symptoms. PLMVd was detected in three nectarine and eight peach trees. The nucleotide sequence of the eleven PLMVd isolates was determined. Like previously studied PLMVd isolates, Turkish isolates varied in length from 336 to 340 nucleotides. Multiple alignments and phylogenic analyses showed that 31 clones of 11 isolates clustered in PLMVd Group III. Three clones of isolate 99 showed the greatest variability among the isolates characterized in this work and 12 previously characterized isolates. mFold analysis of secondary structures of the three clones of isolate 99 showed that most of the variations are located in a stem involved in the pseudoknot structure, in loop 10 and in the hammerhead arm region. PLMVd isolate 99 showed a high identity with isolate 162.4 from peach cv. Early May Crest.