An experimental design to test the effect of wheat variety mixtures on biodiversity and ecosystem services

Abstract

Website: https://www6.inra.fr/wheatamix The present document details how the Wheatamix consortium, inspired by ecological experiments exploring relationships between plant biodiversity and ecosystem functioning (e.g. the Jena experiment Weisser et al. 2017), selected bread wheat (Triticum aestivum L.) lines, phenotyped them across a range of functional traits and used this information to set up an experimental design able to unravel the effects of variety number and of the functional diversity and identity within variety mixtures for evaluating the impact of intraspecific crop diversity on a range of ecosystem services. Wheat line selection The Wheatamix project investigates the potential benefits of variety mixtures in the Paris basin wheat supply chain, and therefore focuses on varieties and lines adapted to the local climate. A consensus list of 57 wheat lines (Table 1) was thus settled on these grounds and to meet the expectations of agronomists, geneticists, phytopathologists and ecophysiologists of the group. This list is composed of i) 32 elite bread wheat varieties registered in the French catalogue, selected for their high yields under conventional farming, ii) 5 modern varieties bred for organic farming (OF), iii) 10 landraces resulting from farmers' mass-selection, cultivated in France in the early 1900es, and iv) 11 lines from an INRA-MAGIC multiparental and highly recombinant population (Thepot et al., 2015), adapted to Northern France. Due to the heterogeneity of information available for each variety and line, various criteria were used for this selection. The 32 elite bread wheat varieties were chosen on the basis of their wide use in the Paris Basin, and to ensure representativeness of the diversity for earliness, disease resistance or bread-making quality, using the available information in the variet