A genetic analysis of weed competitive ability in spring wheat

Reid, T. A., Navabi, A., Cahill, J. C., Salmon, D. and Spaner, D. 2009. A genetic analysis of weed competitive ability in spring wheat. Can. J. Plant Sci. 89: 591-599. Competition with weeds decreases crop yields globally. Breeding for competitive ability against elevated weed pressure can be difficult because the selection for specific traits which contribute to competitive ability may result in yield losses. The widely Studied International Triticeae Mapping Initiative (ITMI) population was used to study the genetics of traits associated with competitive ability in a high latitude (52-53 degrees N) wheat-growing environment in central Alberta, Canada. Grain yield without weed competition and under ex peri men tally sown cultivated oat competition exhibited similar heritability. Grain yield was positively correlated with early season vigour, and negatively correlated with days to maturity in the competitive treatment only. In this study, similar heritability estimates between competition treatments suggest that selection in a weed free environment can lead to improvements in a weedy environment, but some high-yielding lines under competition would be eliminated during selection.