Investigation on occurrence of Tricho-, Fovea- and Capilloviruses in ancient fruit tree cultivars in Campania.

摘要

The occurrence of Apricot pseudochlorotic leaf spot virus (APCLSV), a recently described Trichovirus closely related to Apple chlorotic leaf spot virus (ACLSV), was investigated in ancient local fruit tree cultivars in Campania, Italy, during 2004 and 2005. Samples collected from 361 symptomatic and asymptomatic trees were analysed by nested RT-PCR. APCLSV was detected in 7 of 112 apricot trees, one of 29 peach trees, and 2 of 26 plum trees. All the apple, pear and cherry trees were negative for APCLSV. The sequences of APCLSV PCR products showed an average pairwise divergence of 11.6% (nucleotide sequences) and 4.5% (amino acid sequences). The majority of the isolates clustered with some previously characterized isolates, but three additional divergent clusters could be identified. The results confirmed the variability of APCLSV and that contrary to ACLSV, APCLSV could be restricted to stone fruit hosts. Forty-eight samples were also screened for the presence of viruses belonging to the Trichovirus, Foveavirus and Capillovirus genera by PDO nested RT-PCR. The results revealed a very high prevalence of ACLSV in all species. Additional viruses detected included Cherry green ring mottle virus (2 of 4 cherry trees), Apricot latent virus (1 of 14 apricot trees), Cherry virus A (6 of 14 apricot trees, one of 6 plum trees, and one of 4 cherry trees), Apple stem pitting virus (4 of 9 apple trees and 1 of 8 pear trees) and Apple stem grooving virus (1 of 9 apple trees and 1 of 8 pear trees). This is the first record of APCLSV on peach in Campania and of CVA in Italy.