Plant functional trait variability and trait syndromes among wheat (Triticum aestivum) varieties: the footprint of artificial selection
Abstract Although widely used in ecology, trait-based approaches are seldom applied to study agroecosystems. In particular, how functional trait variability among varieties of a crop species compares to the variability among wild plant species and how variety selection can modify trait syndromes needs to be evaluated. Here, we quantified 18 above- and belowground functional traits for 57 varieties of common wheat, representative of different modern selection histories. We compared trait variability between varieties and between Pooideae species and analyzed the effect of selection histories on trait values and trait syndromes. For traits under strong selection, trait variability among varieties was less than 10% of the variability observed between Pooideae species. But for traits not directly selected like root N uptake capacities, the variability was up to 75% of the variability among Pooideae species. Ammonium absorption capacity by roots was counter-selected for conventional varieties as compared to organic varieties and landraces. Artificial selection also altered some trait syndromes classically reported for Pooideae. Identifying traits for which high or low variability is present among varieties and characterizing the hidden effects of selection on trait values and syndromes will benefit the selection of varieties to be used especially for lower N input agroecosystems.