Pomegranate

A pomegranate contains many seeds.  It symbolises having many children.  In chinese, pomegranate is pronounced as shi liu (石榴）.  The first word shi also sounds like generation (世）.  Hence, pomegranate has the symbolic meaning of having generation after generation of offsprings.

It is grouped together with peach and citron to convey auspicious message of 3 abundances (Sanduo)