  Let E(1)_K denote the closed 4-manifold that is homotopy equivalent (hence
homeomorphic) to the rational elliptic surface E(1) and is obtained by
performing Fintushel-Stern knot surgery on E(1) using a knot K in S^3. We
construct an infinite family of homologous non-isotopic symplectic tori
representing a primitive homology class in E(1)_K when K is any nontrivial
fibred knot in S^3. We also show how these tori can be non-isotopically
embedded as homologous symplectic submanifolds in other symplectic 4-manifolds.
