Thank you, Luis. I couldn't find that option to add the arguments in gl.blast() but I believe it wouldn't work as the function generate several reports, which are needed to be analyzed independently.
For instance, I need to do this: blast1_df <- as.data.frame(gl.print.reports(1))
Actually, gl.blast() tells you at the end to run gl.list.reports() and gl.print.reports(). So maybe that could be clarified for the next version :)
I installed dartR in order to be able to run the function.
Cheers!
Claudia