  We study the effect of environment on the properties of type Ia supernovae by
analyzing the integrated spectra of 57 host galaxies. Integrated spectra of
galaxies best represent the global properties of the host and can be used to
directly compare with spectra of high-redshift galaxies. From the spectra we
deduce the metallicity, current star-formation rate and star-formation history
of the hosts and compare these to the supernova decline rate which is an
indicator of the luminosity. Our results show no significant correlation
between spiral host galaxy metallicity and SNIa light curve decline rate. The
Hydrogen-alpha equivalent width (EW) of the host galaxy is an indicator the
current star-formation rate compared to average rate in the past. The range of
SNIa luminosities increases with decreasing EW which suggests that the
variation in SNIa {56}Ni production is primarily due to progenitor mass and
population age.
