▎ 摘　　要

We theoretically demonstrate that a kind of extended line defect, an experimentally available topological defect in graphene lattice, can induce one-dimensional boundary states. And in the presence of the pseudomagnetic field generated by an inhomogeneous strain, such boundary states are valley chiral in the sense of electronic propagation direction being locked to its valley degree of freedom. Based on such an electronic characteristic, we further show that when the line defect is embedded in the strained graphene strip, the valley filtering and valley valve functions can be realized in the electronic transport process. Therefore, we argue that the line defect can play a key role in the field of graphene valleytronics, instead of a zigzag-edged graphene nanoribbon. Copyright (C) EPLA, 2015