  A model for the universe with tachyonic and fermionic fields interacting
through a Yukawa-type potential is investigated. It is shown that the tachyonic
field answers for the initial accelerated regime and for the subsequent
decelerated regime so that it behaves as an inflaton at early times and as a
matter field at intermediate times, while the fermionic field has the role of a
dark energy constituent, since it leads to an accelerated regime at later
times. The interaction between the fields via a Yukawa-type potential controls
the duration of the decelerated era, since a stronger coupling makes a shorter
decelerated period.
