Twenty years of evolution and diversification of digitaria streak virus in Digitaria setigera

Within the family Geminiviridae, the emergence of new species results from their high mutation and recombination rates. In this study, we report the variability and evolution of digitaria streak virus (DSV), a mastrevirus isolated in 1986 from the grass Digitaria setigera in an island of the Vanuatu archipelago. Viral DNA of DSV samples was amplified from D. setigera specimens, derived from the naturally infected original plant, which were propagated in different laboratories in France and Italy for more than twenty years. From the consensus sequences, the nucleotide substitution rate was estimated for the period between a sample and the original sequence published in 1987, as well as for the period between samples. In addition, the intra-host genetic complexity and diversity of 8 DSV populations with a total of 165 sequenced haplotypes was characterized. The evolutionary rate of DSV was estimated to be between 1.13 × 10-4 and 9.87 × 10-4 substitutions/site/year, within the ranges obser...