[BioC] Directed MST (Edmond's Algorithm)

[Forst, Christian]

I am looking for an implementation of Edmond's (or better) algorithm to calculated a directed minimum spanning tree from a directed graph. I found the edmondsOptimumBranching() function in the RBGL package but I am struggling in getting my graphs (from edge-lists) in the right format. I would guess using addEdge() is not the way to go to read large graphs. 
I am open for suggestions for other packages.

thanks
  Christian