  We estimate the fraction of star forming galaxies in a catalogue of groups,
constructed from the 2dF galaxy redshift survey by Merch\'an & Zandivarez. We
use the $\eta$ spectral type parameter of galaxies and subdivide the sample of
galaxies in groups into four types depending on the values of the $\eta$
parameter following Madgwick et al. We obtain a strong correlation between the
relative fraction of galaxies with high star formation and the parent group
virial mass. We find that even in the environment of groups with low virial
mass $M \sim 10^{13} M_{\odot}$ the star formation of their member galaxies is
significantly suppressed. The relation between the fraction of early-type
galaxies and the group virial mass obeys a simple power law spanning over three
orders of magnitude in virial mass. Our results show quantitatively the way
that the presence of galaxies with high star formation rates is inhibited in
massive galaxy systems.
