韭葱黄条病毒、洋葱黄矮病毒和胡葱黄条病毒六安分离物CP基因克隆及同源性分析

CP gene cloning and sequence analysis of Liu'an isolates of Leek yellow stripe virus,Onion yellow dwarf virus and Shallot yellow stripe virus

设计特异性引物PCR扩增了六安大蒜病样中的韭葱黄条病毒(Leek yellow stripe virus,LYSV)、洋葱黄矮病毒(Onion yellow dwarf virus,OYDV)和胡葱黄条病毒(Shallot yellow stripe virus,SYSV)的全长CP基因,插入到pGEM-T载体并测序。分别比较3种病毒CP基因种内变异性和种间亲缘关系。结果表明LYSV六安分离物CP基因由864个碱基组成,与Genbank上已报道的68个LYSV不同分离物CP基因的核苷酸序列同源性为76.12%～84.31%;OYDV的CP基因由771个碱基组成,与Genbank上已报道的86个OYDV不同分离物同源性为81.06%～90.40%;SYSV的CP基因由774个碱基组成,与Genbank上已报道的11个SYSV不同分离物CP基因同源性为88.63%～94.32%;从分析结果来看,LYSV的CP基因不同分离物之间变异性较大,OYDV CP变异性不大,SYSV变异性很小;3种病毒都有1个以上的宿主,病毒种内不同宿主分离物之间CP序列差异很小。进化分析显示OYDV和SYSV的CP基因亲缘性较近并成簇,LYSV的CP基因与OYDV和LYSV的CP基因亲缘性较远。

Specific primers were designed to amplify CP genes of Leek yellow stripe virus（LYSV）,Onion yellow dwarf virus（OYDV）and Shallot yellow stripe virus（SYSV）Liu＇an isolates.Then the CP genes were cloned into pGEM-T vectors and were sequenced.Sequence analysis indicated that CP genes of LYSV,OYDV and SYSV Liu＇an isolates consists of 864,771 and 774 nucleotide acids respectively.Multiple aligments showed that CP gene of LYSV Liu＇an isolate shared 76.12%-84.31% nucleotide acids identities with 68 LYSV CP genes reported on Genbank,CP gene of OYDV Liu＇an isolate shared 81.06%-90.40% nucleotide acids identities with 86 OYDV CP genes reported on Genbank and CP gene of SYSV Liu＇an isolate shared 88.63%-94.32% nucleotide acids identities with 11 SYSV CP genes reported on Genbank.These results indicated that the divergence in LYSV CP among different isolates was high,whilst divergence of OYDV CP was moderate in different isolates.All the results indicated that the variability of LYSV CP gene among different isolates was high,OYDV CP gene among different isolates was in the middle and SYSV CP gene among different isolates was low.Phylogenetic analysis showed that LYSV CP had little relationship with OYDV CP and SYSV CP and OYDV had closer relationship with SYSV than LYSV.