OCCURRENCE OF PEACH LATENT MOSAIC VIROID IN CHINA AND DEVELOPMENT OF AN IMPROVED DETECTION METHOD
C. Turturo, A. Minafra, H. Ni, G. Wang, B. Di Terlizzi, V. Savino
Peach latent mosaic viroid (PLMVd) was detected by indexing on peach ‘GF-305’ seedlings and by molecular hybridization with a digoxigenin-labelled riboprobe, in 9 out of 14 peach samples from the Liaoning province of the People’s Republic of China. For molecular assays four different tissue processing methods were compared, two involving total nucleic acid (TNA) extraction with or without organic solvents followed by formaldehyde or alkaline denaturation, and two based on direct denaturation of crude leaf sap. All extracts, regardless of the method used, gave positive hybridization signals, but alkaline denaturation increased the sensitivity of detection in both TNA and crude sap preparations. Because of its simplicity and minimal manipulation, alkaline denaturation of crude sap appears to be the best method for routine detection of PLMVd.