The Detection Of Prunus Necrotic Ringspot Virus And Prune Dwarf Virus On The Stone Fruit Trees By Serology And RT-PCR

The stone fruit trees was worldwildly cultivated, and in southern China, peach, plum, apricot and nectarine are the most popular stone fruit trees. Prunus necrotic ringspot virus (PNRSV) and Prune dwarf virus (PDV) were the two important viruses in stone fruit trees, which could cause different symptoms and decrease growth and productivity in infected trees. The establishment of highly efficient detection methods could provide useful tools for preventing the transmission and reduce their damage. In this study, three methods including biological indexing, PAS-ELISA and molecular techniques were used for the detection of PNRSV and PDV in peach, plum, apricot and nectarine. The main results are as following.1. Totally 127 samples of peach, plum, apricot and nectarine were collected from Wuhan, Xianning, and other regions of Hubei province. PNRSV and PDV were detected from these samples by PAS-ELISA. The results showed that the total detected percentages of PNRSV and PDV were 26.8% and 16.5%, respectively. The detected percentages of PNRSV and PDV were 25.9% and 16.7% from 54 samples of peach, 35.3% and 29.4% from 17 samples of plum, 25.0% and 15.0% from 20 samples of apricot, 25.0% and 11.1% from 36 samples of nectarine, respectively. The complex infection rates of these two viruses was 14.2%.2. Crude extracts from samples showed positive reaction in PAS-ELISA were mechanically inoculated onto herbaceous indicator plants Cucumis sativus and Chenopodium quinoa for biological indexing in green house. Results showed that the obvious local and systemic symptoms were induced by the inoculation on these two indicators. The symptom inducing rates for detected samples was 5/10 for peach samples and 5/6 for plum samples. Two out of 9 nectarine samples induced mild symptoms on Cucumis sativus, but no one of 5 apricot samples induced symptom on any of these indicators. 3. The total RNA was extracted from some samples showing positive reaction for PNRSV and PDV in both PAS-ELISA and biological indexing and used as templates for Reverse Transcription Polymerase Chain Reaction (RT-PCR). Primers targeting to specific sites of cp genes of both PNRSV and PDV were used for RT-PCR detection of these two viruses. The target products with expected sizes 449bp for PNRSV and 172bp for PDV were amplified from all tested samples.