Biological and molecular properties of Prune dwarf virus cherry isolates from Bulgaria.

Biological and molecular properties of five Prune dwarf virus cherry isolates were studied. Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) proved PDV infection in the respective source trees and absence of six other viruses infecting the cherry. Two of infected source trees were symptomless, and the other three trees showed deformed and elongated leaves with chlorotic lines and spots. The reaction of greenhouse-grown seedlings of 22 herbaceous test plant species was investigated. The woody indicators Prunus tomentosa and Prunus cerasifera were chip-budded. Cucumis sativus cv. Amelia, C. sativus cv. Levina, C. sativus cv. Tessa and Prunus tomentosa appeared as the most suitable test plants for bioassay of studied PDV isolates. The nucleotide sequences corresponding to the full-length coat protein (CP) of 657 bp were obtained. The identity among studied isolates in CP was 95.5–100% and 97.4–100% at nucleotide and amino acid levels, respectively. The movement protein (MP) sequences were 753 nucleotides long, translating 251 amino acids and shared 94.1–98.4% nucleotide and 96.8–99.2% amino acid identity. Constructed trees with the nucleotide sequences of both MP and CP genes of studied isolates and referent PDV cherry variants showed the formation of two phylogroups in the two genomic regions. All studied isolates separated into two clusters in group I. No correlation between the phylogenetic grouping and the biological properties, as well the geographical origin, was observed. [ABSTRACT FROM AUTHOR]