甘肃省定西市玉米坏死条纹病毒分离物的分子鉴定及全基因组序列分析OA

To identify the pathogen associated with chlorotic streak symptoms in maize(Zea mays)in Dingxi City,Gansu Province,high-throughput sequencing combined with reverse transcription-poly-merase chain reaction(RT-PCR)and 5′/3′ rapid amplification of cDNA ends(5′/3′ RACE)was used to identify the virus and determine its complete genome sequence.Sequence characteristics and phyloge-netic relationships were analyzed using NCBI BLAST,MegAlign,and IQ-TREE.RT-PCR was further used to investigate the occurrence and distribution of the virus in different regions of Gansu Province.The results showed that maize necrotic streak virus(MNeSV)was identified from symptomatic maize samples collected in Dingxi City and the isolate was designated MNeSV-DX.The complete genome of MNeSV-DX was 4 094 nt in length and contained five predicted open reading frames.Its genomic orga-nizationwas identical to that of the US isolates(GenBank accession numbers NC_007729.1 and AF266518.2).The complete genome shared 98.8％nucleotide sequence identity and 99.0％amino acid sequence identity with these reference isolates.Phylogenetic analysis demonstrated that the three iso-lates clustered within the same clade,indicating a close evolutionary relationship with limited genetic divergence.RT-PCR detection further demonstrated the presence of MNeSV in maize samples collected from Dingxi,Gannan,and Longnan in Gansu Province.These findings indicate that MNeSV can natu-rally infect maize in China and is closely associated with the chlorotic streak symptoms observed in Dingxi City,highlighting the need for increased attention to the occurrence and spread of this virus.