first thing you want to do is bend back that rod to make sure that it fits snug into the hole again, if it has bent since being broken.
The two things I would try to fix this would be Epoxy, or liquid nails. I would go with liquid nails first (found in in the glue/tube sealant aisle of a Home Depot or Lowe's. This stuff is used to lay tiling work, so it should bond good with the resin. Just add a tiny bit though. Enough so that it doesn't come spewing out the cracks when you press it flush together. Put on a song or two to listen to, and just hold it in place and be patient. It should dry fast, in just a couple of minutes. Depending on if any small chipping happened when it broke, you may want to get some black, or dark brown/green paint to cover up the white resin still showing through any cracks.
That should do it! It looks like a clean break, so it should bond together pretty well.