Recent Advances in Wheat Allelopathy

Wheat (Triticum aestivum), as one of the world's important crops, has been studied in depth for its allelopathic potential in weed management. Research on wheat allelopathy has progressed rapidly from the initial evaluation of allelopathic potential to the identification of allelochemicals and genetic markers associated with wheat allelopathy. Allelopathic activity varied among wheat accessions. Significant varietal differences in the production of allelochemicals were also found. In comparison with weakly allelopathic accessions, strongly allelopathic accessions produced significantly higher amounts of allelochemicals in the shoots or roots of young seedlings, and also exuded larger amounts of allelochemicals into the growth medium. Genetic markers associated with wheat allelopathy and plant cytochrome P450s encoding the biosynthesis of wheat allelochemicals have been identified. Recent advances in metabolomics,transcriptomics and proteomics will greatly assist in the identification of novel allelopathygenes. Ultimately, the allelopathy genes could be manipulated to regulate the biosynthesis of allelochemicals, thereby resulting in better weed suppression via elevated levels of allelopathic potential in commercial wheat cultivars.