来源于新疆的3个苹果褪绿叶斑病毒分离物的分子变异研究

Molecular diversity of three Apple chlorotic leaf spot virus isolates from XinJiang

苹果褪绿叶斑病毒（Apple chlorotic leaf spotvirus,ACLSV）可侵染多种仁果类和核果类果树,广泛分布于世界各个果产区。该病毒侵染苹果树一般不产生明显症状,

Apple chlorotic leaf spot virus（ACLSV） isolates from Korla pear（KI-2）,New pear no.7（XI-1） and Red Fuji apple（API-4） were collected from XinJiang and characterized by analyzing sequences of their near genomic 3′-terminal.The RT-PCR products were cloned,and analyzed by single-strand conformation polymorphism（SSCP）.Eight out of 39 collected positive clones showing different SSCP patterns were sequenced.The results showed that the amplified products had sizes ranging 676-703 bp,including partial coat protein（CP） gene（506 bp,accounts for 87% of the complete cp gene） and 3′-terminal non-coding region（3′ NCR） sequences.The cp gene sequences from isolate KI-2 showed a high intra-isolate divergence,with 84.8%-85.4% identities at the nucleotide（nt） level,and the intra-isolate identities were 99.8 % and 92.5%-99.8 % for isolate XI-1 and API-4,respectively.Phylogenetic analysis on the nt sequences of cp gene showed that the analyzed ACLSV variants from three isolates fell into two different clusters.A variant KI-2-6 from KI-2 was clustered into a group with an apple isolate aclsv-c from China and a plum isolated from France,and all other variants fell into a large cluster.The 3′ NCR sequences of these variants were identical ranging 80.6%-100 %.