In order to investigate the genetic diversity and molecular evolution of Cucumber mosaic virus(CMV)on tobacco in Hunan province,303 suspected diseased samples from tobacco-growing areas in Hunan were detected,and the phylogeny,genetic variation and population structure of CMV were analyzed.The coat protein(CP)genes of some samples were cloned and compared with CMV isolates registered on NCBI.The results showed that the sequence of CP from Hunan isolates shared identity of 86.34%-98.42%with isolate from NCBI.Phylogenetic analysis showed that CMV...