大豆双生病毒B丹参分离物的基因组结构分析及遗传变异研究OA

Salvia miltiorrhiza is one of the major traditional Chinese medicinal plants in China.Virus diseases are widespread in S.miltiorrhiza in Henan province.Soybean geminivirus B(SGVB)was first detected in S.miltiorrhiza in Henan.To elucidate the genomic structure and genetic diversity of the soybean geminivirus B Salvia miltiorrhiza isolate(SGVB-SM),the complete genome sequences of eight SGVB-SM isolates were obtained using PCR.The genome of SGVB-SM is 2 625 nucleotides(nt)in length and encodes four proteins:a 256-amino acid(aa)coat protein(CP),a 97-aa movement protein(MP),a 163-aa C1 protein,and a 293-aa C2 protein.Nucleotide sequence identity analysis revealed that the eight SGVB-SM isolates shared 93.5％to 95.0％identity across the whole genome with the Korean SGVB-Kong isolate.The nucleotide identities of CP,MP,C1,and C2 ranged from 93.9％to 98.3％,88.4％to 95.2％,93.3％to 95.9％,and 93.7％to 95.6％,respectively,while the corresponding amino acid identities were 93.1％to 100％,90.5％to 100％,91.7％to 100％,and 100％,respectively.Further analysis of CP sequences from 33 SGVB-SM isolates demonstrated that nucleotide and amino acid identities among these isolates were 90.9％to 96.5％and 92.2％to 94.9％,respectively.Compared with the Kong isolate,the nucleotide and amino acid identities ranged from 93.9％to 98.3％and 93.1％to 100％,respectively.The CP gene of SGVB-SM isolates is 768 nt in length.Phylogenetic analysis showed that SGVB-SM isolates clustered in the same branch as the SGVB-Kong isolate.Recombination analysis revealed seven recombination events in six SGVB-SM isolates,with recombination regions mainly located between 1 040 nt and 2 618 nt.This study enriches the sequence information of SGVB and contributes to a better understanding of the genetic evolutionary relationships of this virus population.