Allelopathic potential of Triticum spp., Secale spp. and Triticosecale spp. and use of chromosome substitutions and translocations to improve weed suppression ability in winter wheat

A search was carried out for allelopathic sources among accessions of Triticum, Secale, Triticosecale and wheat-rye substitution and translocation lines to be used in breeding programmes to improve weed suppression ability of wheat. A bioassay with mustard as target plants was used for the screening. Mustard was chosen among seven tested target plants because it showed a particular high root growth inhibition when grown together with rye compared with wheat. None of the Triticum accessions studied showed potential allelopathic activity of interest for breeding, but most Triticosecale did. Several of the wheat-rye substitution and translocation lines also showed high allelopathic activity. The highest activity was found in lines with a substitution of 1R or 2R. Some multiple substitution lines and lines with only rye chromatin also showed high allelopathic activity. It is suggested that in vitro selection of wheat-rye substitution lines with high allelopathic potential with a bioassay with mustard as target plants could be used to improve weed suppression ability of wheat.