Definitely not, for the reasons the others have stated above. In a 25 litre tank, I would only put a betta and a snail.
Anything under 10 gallons, IMO, isn't enough for any fish other than a betta.
It would be a bad idea, not just because the Betta will most likely attack the guppies because of their long flowing tails, but another reason is because that tank IMO is too small for that mix, even if they were compatible a 25 liter is too small for a Betta and guppies