Dislocation plasticity conventionally induces textures in polycrystalline metals after a large deformation. We used parallel molecular dynamics to simulate the plastic deformation of nanocrystalline copper to an isochoric stretch up to 100% logarithmic strain. We found that the movements of partial dislocations that dominate the deformation process do not lead to texture formation. The grain size distribution becomes extremely inhomogeneous. By observing the structural evolution, we demonstrate that grain growth assisted by partial dislocations suppresses the texture formation.