Allelopathy in weedy rice as a genetic resource for developing competitive rice varieties

Abstract

Weedy rice is of the same species as cultivated rice, Oryza, and is a common rice weed exhibiting allopathic characteristics. Incorporation of allelopathic traits from weedy rice into cultivated rice may have a positive impact on rice yield. The overall objective of this study was to characterize weedy rice accessions based on the allelopathic potential to suppress barnyardgrass. These accessions, once discovered, may be used in identifying phenotypic traits and genes associated with their weed suppressive trait. Ten weedy rice accessions, and five rice cultivars (Rex, CL163,Rondo, PI312777, PI338046) were screened using a stair-step technique. The allelopathic potential was calculated based on the percent inhibition of barnyardgrass. The best performing accessions were phenotyped for root characteristics in a lab setting. Lastly, 30 SSR markers were used to evaluate the weedy rice to identify markers associated with the trait. Accessions identified in this study should be considered in the development of weed-suppressive rice cultivars.