Zero-sum partition theorems for graphs

Let q=pn be a power of an odd prime p. We show that the vertices of every graph G can be partitioned into t(q) classes V(G)=⋃t=1t(q)Vi such that the number of edges in any induced subgraph 〈Vi〉 is divisible by q, where t(q)≤32(q−1)−(2(q−1)−1)124