Molecular marker-assisted detection of rice weevil in stored rice

Abstract

Stored cereal crops form the major component of the world's food supply. It is well known that post-harvest crop losses, due to insects and microbes, cause significant economic waste in both developed and developing countries. In general, the environment in storage facilities is prone to rapid pest development, leading to significant grain losses. Rice weevil (Sitophilus oryzae L.) is one pest of cereal crops that deposits its eggs on or in a seed. To detect rice weevil in stored rice, we developed PCR-based molecular markers of Sitophilus oryzae. Several sets of PCR primers from the ‘internal transcribed spacer 2’ gene of S. oryzae were analyzed to identify molecular markers that are specific to the S. oryzae genome. Among six sets of molecular markers identified, three were found to be useful for identifying rice weevil. Our results demonstrate that a PCR marker system permits rapid and reliable identification of weevil in stored grain. Furthermore, this PCR assay would expand the choice of tools for monitoring populations of the weevil in pest management programmes.