  The supersymmetric sector of minimal supersymmetric standard model (MSSM)
possesses a U(1) R-symmetry which contains Z_2 matter parity. Non-zero neutrino
masses, consistent with a 'redefined' R-symmetry, are possible through the
see-saw mechanism and/or a pair of superheavy (mass M) SU(2)_L triplets with
vev of order M^2_W/M. If this R-symmetry is respected by the higher order
terms, then baryon number conservation follows as an immediate consequence. In
the presence of right handed neutrinos, the observed baryon asymmetry of the
universe arises via leptogenesis. An interplay of R- and Peccei-Quinn symmetry
simultaneously resolves the strong CP and mu problems.
