Genetic diversity and population structure of Sugarcane streak mosaic virus in Yunnan province, China

Abstract

Sugarcane streak mosaic virus (SCSMV) is one of the most important pathogens associated with sugarcane mosaic disease. In recent years, the rapid spread of SCSMV in Yunnan province, China, has raised concerns. In this study, we analyzed 110 sugarcane samples with mosaic symptoms taken from main growing areas in Yunnan province. RT-PCR detection results showed that 94% samples were positive for SCSMV. We subsequently analyzed the genetic diversity and population structure of SCSMV based on the coat protein (CP) sequences of 48 isolates. The overall mean value of nucleotide diversity for all isolates was 0.01127 ± 0.00082. Phylogenetic analysis based on CP gene sequences showed that all the Chinese isolates were clustered into one group, showing a distinct geographic feature. Analysis of population structure showed that the population from this study is not genetically different from that in China, but is genetically different from populations from other countries. Our results suggest that SCSMV has become the main pathogen of sugarcane mosaic disease in Yunnan province, China and that the recent rapid spread of SCSMV in Yunnan is not due to the invasion of new SCSMV populations.