  Using CSW rules for constructing scalar Feynman diagrams from MHV vertices,
we compute the contribution of $\mathcal {N}=1$ chiral multiplet to one-loop
MHV gluon amplitude. The result agrees with the one obtained previously using
unitarity-based methods, thereby demonstrating the validity of the MHV-diagram
technique, in the case of one-loop MHV amplitudes, for all massless
supersymmetric theories.
