Comparison of the RNA2 Segments Between Chinese Isolates and Japanese Isolates of Rice Stripe Virus

Abstract：The complete nucleotide sequences of the RNA2 of two Chinese isolates of Rice stripe virus are determined．One is isolated from endemic sites at Chuxiong(cx)，Yunnan Province。the other is isolated from outbreak sites at Hongze(HZ)，Jiangsu Province．Th e total nucleotide sequences of the RNA2 Of RSV CX and RSV HZ are 3506 bp an d 35 14 bp long．respectively．W hen compared with RNA2 Of T and O isolates of Japan ．we find that these four isolates could be divided into two groups． HZ．T and O isolates share 97．2％ ～98．O％ an d 96．8％ ～97．1％ identities in vORF2 an d VCORF2 at the nucleotide leve1．respectively an d form one group．The sequences in 5 an d 3 terminal non-encoding region are completely identical among these three isolates．In this group．HZ isolate is more closely related to T isolate than to O isolate．Th e length of intergenic region fIR)of HZ isolate iS the same as those of T and O isolates．CX isolate belongs to an other group．which shares only 95．0％ ～95．7％ an d 93．9％ ～94．4％ sequences identities in vORF2 an d VCORF2 between two groups at the nucleotide leve1． respectively．Th ere is a deletion of 8 nt in length in the IR Of CX isolate compared with HZ isolate．Even though no base variation occu~ed in 5 terminal non．coding region，there is one base substitution in 3’terminal non—coding region between CX and HZ isolates．These results show that the isolates aregrouped according to their geographical location． Additionally， highly consensus in 5 and 3non—encod ing region suggests that these regions play a very important role in tran scription andreplication of viral genome．Finally，the molecular epidemiology and gene functions of RSV arediscussed in this paper．