Detection And Sequence Diversity Analysis Of Viroids Isolated From Jujube Tree In China

Ninety-five Jujube tree samples were collected from Cangzhou, Baoding and Handan in Hebei provinceof China. These samples were used for detection and sequence diversity analysis of viroids. Lowmolecular weight RNAs were extracted and used for Dot-blot Hybridization , ReverseTranscription-Polymerase Chain Reaction (RT-PCR), Two-Dimensional PAGE (2-D-PAGE) andTransfer Membrane for Hybridization and Biological Indexing. Results showed that the 2 Jujube treesamples which were collected from the same field of "Jujube tree-pear" intercroping in Qiqiao,Cangzhou were positive for Hop stunt viroid (HSVd). The other two areas were all not detected HSVdin Jujube trees. The detection rate was 2.1%.This is the first report of HSVd in Jujube trees in the world.Both of the 2 samples were selected for cloning, sequence analysis of HSVd and then comparing withthe first HSVd sequence (X00009,1983) from the Hop and also the HSVd sequences in GenBank.Results indicated that:1. Each of 2 HSVd sequences were cloned from CZ3 and CZ4, then campared with the HSVd sequence (X00009,1983) which was first report from the Hop, the results showed that 25 gene sites had been mutated, they had low homology.2. The HSVd sequences in Jujube tree from China were relatively conserved and each of the HSVd sequence Blast in GenBank showed that homologys were from 92% to 100%, and there were no clear relativity among sequence variation, region and host.