The Planetary Nebulae Populations in the Local Group
  Planetary nebulae have been used as tracers of light and kinematics for the
stellar populations in early-type galaxies since more than twenty years.
Several empirical properties have surfaced: for example the invariant bright
cut-off of the planetary nebulae luminosity function and correlations of the
luminosity specific PN number with the integrated properties of the parent
stellar populations. These observed properties are poorly understood in terms
of a simple model of a ionized nebula expanding around a non-evolving central
star. In order to make further steps, we need to study self-contained systems
at know distances whose PN populations are sufficiently nearby to permit
investigation into their physical properties. The galaxies in the Local Group
represent a valid proxies to study these late phases of evolved stellar
populations with a spread of metallicities, $\alpha$-element enhancements, and
star forming histories.
