Identification of Rice Dwarf Disease in Jiangsu

Specific primers RB-S7-F/R and SRB-S7-F/R were designed according to the published sequence of S7 segment of rice black-streaked dwarf virus(RBSDV) and southern rice black-streaked dwarf virus(SRBSDV).Subsequently the pathogen of rice dwarf disease,which was prevalent in Jiangsu province in 2009,was identified by RT-PCR,sequencing and sequence alignment methods.The results showed that a purposed 1 200 bp fragment was cloned with RB-S7-F/R primer and wasn′t with SRB-S7-F/R in 36 of 47 detected rice samples.The sequence of this fragment shared 93.3%-100% nucleotide homology and 97.4%-100% amino acid homology with the sequence of the corresponding one in S7 of RBSDV and shared 77.4%-79.5% homology with SRBSDV.The similar result was obtained by phylogenetic relationships analysis.All above demonstrated that the pathogen of rice dwarf disease occurred in Jiangsu in 2009 was RBSDV and SRBSDV hadn′t been found in Jiangsu province.