两个马铃薯Y病毒黑龙江马铃薯分离物株系鉴定

为明确分离自黑龙江省克山县马铃薯上的2个病毒分离物KS4和KS7的分类地位,通过RTPCR扩增、克隆获得其基因组序列,利用重组分析程序包和最大似然法分别进行重组分析和系统发育分析。结果显示,分离物KS4和KS7的开放阅读框均有9 186个核苷酸,编码3 061个氨基酸,分离物KS4的核苷酸和氨基酸序列均与马铃薯Y病毒(potato virus Y,PVY)分离物Mb112一致率最高,分别为96.9%和98.4%;分离物KS7的核苷酸序列与PVY分离物12-94一致率最高,为97.4%,其氨基酸序列与PVY分离物SYR-Ⅱ-Be1一致率最高,为97.8%。重组分析表明,分离物KS4和KS7均为分离物N-605和Oz的重组体,其中KS4基因组5′-端的2 392个核苷酸来自分离物N-605,其余核苷酸来自分离物Oz;KS7基因组的第800～2 227个核苷酸和第5 637～8 950个核苷酸来自分离物N-605,其余核苷酸来自分离物Oz。系统发育分析发现,分离物KS4被聚类到N:O株系(PVY~(N:O)),分离物KS7被聚类到NTN株系(PVY~(NTN))b型。

Identification of two potato virus Y isolates from potato in Heilongjiang, China

To identify the taxonomic status of potato virus Y (PVY) isolates KS4 and KS7 collected from potato plants in Keshan County of Heilongjiang Province, China, their genomic fragments were amplified using RT-PCR, cloned and sequenced. Recombination and phylogenetic analyses were conducted with Recombination Detection Package and the maximum-likelihood methods, respectively. The open reading frames of isolates KS4 and KS7 contained 9 186 nucleotides, encoding a polyprotein of 3 061 amino acids. Isolate KS4 shared the highest nucleotide and amino acid identities of 96.9% and 98.4% with isolate Mb112, while isolate KS7 had the highest nucleotide identity of 97.4% with isolate 12-94 and an amino acid identity of 97.8% with isolate SYR-II-Be1. Recombination analysis indicated that isolates KS4 and KS7 were recombinants of isolates N-605 and Oz; the 5''-terminal 2 392 nucleotides of isolate KS4 were from isolate N-605, while the other genomic fragment was from isolate Oz; the 800-2 227 nucleotides and 5 637-8 950 nucleotides of isolate KS7 were from isolate N-605, while the other genomic parts were from isolate Oz. The results of phylogenetic analysis showed that KS4 and KS7 isolates were clustered into group of PVY^N:O and type b of PVY^NTN, respectively.