IDENTIFICATION AND MOLECULAR CHARACTERIZATION OF APPLE DIMPLE FRUIT VIROID IN CHINA

Abstract

In a survey of apple virus diseases in China, typical symptoms of Apple dimple fruit viroid (ADFVd) infections were observed. The presence of ADFVd in samples of symptomatic fruits and symptomless leaves from different apple trees was confirmed by RT-PCR, sequencing and dot blot hybridization. Sequence alignment and RNA structure analysis showed that, compared with isolates and variants reported in Italy, there were two nucleotide variations and an alteration of the secondary structure in the ADFVd variants we isolated. Phylogenetic analysis revealed the four variants from China clustered in a group separate from previously reported isolates and variants from Italy and Japan. This is the first report of the identification and molecular characterization of ADFVd in China.