Euclidean supersymmetrization of instantons and self-dual monopoles

We show that N=1 D=4 Euclidean supersymmetry leads to the complexification of gauge potentials, and that to have a supersymmetric Euclidean D=4 theory which allows for the selfduality of real gauge potentials, the supersymmetry has to be extended to even N, i.e. at least N=2. We also discuss the supersymmetrization of Manton's procedure of using the dimensional reduction D=4 → D=3 to derive self-dual monopoles from instantons. (author)