Wheat plants respond to the presence of neighbours, including blackgrass, by changing the length of their roots, according to authors Stéphanie Swarbreck and Julia Davies.
Blackgrass is a major weed for winter cereals in Europe, that can cause substantial yield loss for wheat and oilseed rape. A low density of blackgrass can lead to a 10% decrease in wheat yield, and herbicide resistance is problematic. Though varietal differences in wheat sensitivity to blackgrass infestation has been noted by farmers in the field, wheat varieties are currently not selected based on this trait.
In this new study, the authors have developed an experimental system that enables detailed analysis of the wheat root system in young plants in the presence of a neighbour, either another wheat plant or a blackgrass individual. Their data show that the presence of a neighbour leads to shorter lateral roots, the fine roots that are responsible for taking up nutrients. This study provides new insights into the effect of the weed on wheat and could allow for screening wheat varieties that show less susceptibility to blackgrass infestation.
This work was supported European Union FP7 Marie Curie International Reintegration Grant, the Gatsby Charitable Foundation, the Broodbank Trust University of Cambridge, and the Newton Trust University of Cambridge.
Finch, J.A., Guillaume, G., French, S.A., Colaço R.D.D.R., Davies, J.M. and Swarbreck, S.M. Wheat root length and not branching is altered in the presence of neighbours, including blackgrass. https://doi.org/10.1371/journal.pone.0178176