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以海口香蕉束顶病株的幼嫩假茎和叶片总DNA为模板,通过反向PCR法克隆了香蕉束顶病毒(Banana bunchy top virus,BBTV)海口分离物(命名为BBTV-HaiKou)的6个DNA组分的全长序列。结果表明,DNA1～6序列全长分别为1106、1040、1058、1040、1013和1082nt。各组分非编码区各包含一个茎环共同区和一个主要共同区,同源性分别为91.55%和88.45%。各组分编码区均编码一个开放可读框(ORF),其中DNA1 ORF内部还有一个小的ORF。序列分析表明,BBTV-HaiKou分离物与其它分离物间的DNA1最为保守,DNA2变异最大。DNA1组分核苷酸序列与亚洲组、南太平洋组各分离物及ABTV(Abacá bunchy top virus)分离物同源性分别为93.1%～99.1%,89.6%～90.7%和76.2%～77.4%,相应的编码蛋白氨基酸序列同源性在BBTV和ABTV中分别为93.4%～100%和85.7%。根据Karan等的分类方法,确定BBTV-HaiKou分离物属于亚洲组成员。
The total DNA of young pseudostem and leaves of banana bunchy top strain in Haikou was used as a template to clone the Banana Bunchy Top Virus (BBTV) Haikou isolate (BBTV-HaiKou) by reverse PCR Full length sequence of DNA components. The results showed that the full-length DNA1 ~ 6 sequences were 1106,1040,1058,1040,1013 and 1082nt respectively. The non-coding regions of each component contained a common stem-loop region and a major common region with homologies of 91.55% and 88.45%, respectively. Each component coding region encodes an open reading frame (ORF) with a small ORF inside the DNA1 ORF. Sequence analysis showed that the DNA1 between BBTV-HaiKou isolate and other isolates was the most conservative, with the largest DNA2 variation. The nucleotide sequence of DNA1 was 93.1% -99.1%, 89.6% -90.7% and 76.2% -77.4%, respectively, with the isolates of the Asian and South Pacific groups and the ABTV (Abacá bunchy top virus) The amino acid sequence homologies of the corresponding encoded proteins were 93.4% -100% and 85.7% in BBTV and ABTV, respectively. According to the classification method of Karan et al., BBTV-HaiKou isolates were identified as members of the Asian group.