Viromic approach reveals differences in the composition, diversity and relative abundance of pumpkin viruses across main growing regions of China

China is the leading country for pumpkin production in the world. As other cucurbits, diseases caused by viruses are among the serious threats to pumpkin production, but our knowledge on the virus species infecting pumpkin plants is fragmentary. To understand the occurrence of viral diseases on pumpkin, we determined the geographical distribution characteristics, relative abundance and evolutionary relationship of pumpkin infected viruses by meta-transcriptome sequencing (RNA-seq) and viromic analysis of 159 samples exhibited typical viral symptoms collected across China in this study. Totally, 11 known and 3 new viruses were identified. Interestingly, 3 new viruses identified in this study should be positive-sense single-stranded RNA virus whose hosts are prokaryotes. The viruses identified in different sampling locations exhibit significant variations in term of virus species and relative abundance. Here, the results provide valuable information for understanding the virus species and their diversity in cultivated pumpkin across major growing regions of China.