Transport measurements of p-type modulation doped pseudomorphic heterostructures show that the interfaces of Si/SiGe in either growth direction have the same high quality. Magneto-transport results indicate that the degeneracy of the heavy and light hole bands at the zone center is lifted. SdH spectra show anomalous resolution of filling factors resulting from the interplay of spin splittings of the adjacent Landau levels anisotropy of the g-factor found for these structures. With a novel stress relieved superlattice substrate, the g-factor anisotropy was found to be greatly reduced. © 1992.