title: Assessment of the Potential Impacts of Wheat Plant Traits across Environments by Combining Crop Modeling and Global Sensitivity Analysis.
abstract: A crop can be viewed as a complex system with outputs (e.g. yield) that are affected by inputs of genetic, physiology, pedo-climatic and management information. Application of numerical methods for model exploration assist in evaluating the major most influential inputs, providing the simulation model is a credible description of the biological system. A sensitivity analysis was used to assess the simulated impact on yield of a suite of traits involved in major processes of crop growth and development, and to evaluate how the simulated value of such traits varies across environments and in relation to other traits (which can be interpreted as a virtual change in genetic background). The study focused on wheat in Australia, with an emphasis on adaptation to low rainfall conditions. A large set of traits (90) was evaluated in a wide target population of environments (4 sites × 125 years), management practices (3 sowing dates × 3 nitrogen fertilization levels) and CO2 (2 levels). The Morris sensitivity analysis method was used to sample the parameter space and reduce computational requirements, while maintaining a realistic representation of the targeted trait × environment × management landscape (∼ 82 million individual simulations in total). The patterns of parameter × environment × management interactions were investigated for the most influential parameters, considering a potential genetic range of +/- 20% compared to a reference cultivar. Main (i.e. linear) and interaction (i.e. non-linear and interaction) sensitivity indices calculated for most of APSIM-Wheat parameters allowed the identification of 42 parameters substantially impacting yield in most target environments. Among these, a subset of parameters related to phenology, resource acquisition, resource use efficiency and biomass allocation were identified as potential candidates for crop (and model) improvement.
authors.affiliation: INRA, UMR1248 AGIR, 31326 Castanet-Tolosan, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Casadebaig
authors.affiliation: CSIRO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St. Lucia, QLD 4067, Australia.
authors.forename: Bangyou
authors.initials: B
authors.lastname: Zheng
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St Lucia, QLD 4350, Australia.
authors.forename: Scott
authors.initials: S
authors.lastname: Chapman
authors.affiliation: CSIRO Agriculture, 203 Tor Street, Toowoomba, QLD 4350, Australia.
authors.forename: Neil
authors.initials: N
authors.lastname: Huth
authors.affiliation: INRA, UR875 MIAT, 31326 Castanet-Tolosan, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Faivre
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, 203 Tor Street, Toowoomba, QLD 4350, Australia.
authors.forename: Karine
authors.initials: K
authors.lastname: Chenu
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology*; D001315:Australia; D019295:Computational Biology; D003198:Computer Simulation; D018556:Crops, Agricultural / Q000235:genetics / Q000502:physiology*; D055864:Droughts; D017753:Ecosystem; D008954:Models, Biological; D019655:Quantitative Trait, Heritable; D011891:Rain; D014908:Triticum / Q000235:genetics / Q000502:physiology*