title: SuMoToRI, an Ecophysiological Model to Predict Growth and Sulfur Allocation and Partitioning in Oilseed Rape (Brassica napus L.) Until the Onset of Pod Formation.
abstract: Sulfur (S) nutrition in rapeseed (Brassica napus L.) is a major concern for this high S-demanding crop, especially in the context of soil S oligotrophy. Therefore, predicting plant growth, S plant allocation (between the plant's compartments) and S pool partitioning (repartition of the mobile-S vs. non-mobile-S fractions) until the onset of reproductive phase could help in the diagnosis of S deficiencies during the early stages. For this purpose, a process-based model, SuMoToRI (Sulfur Model Toward Rapeseed Improvement), was developed up to the onset of pod formation. The key features rely on (i) the determination of the S requirements used for growth (structural and metabolic functions) through critical S dilution curves and (ii) the estimation of a mobile pool of S that is regenerated by daily S uptake and remobilization from senescing leaves. This study describes the functioning of the model and presents the model's calibration and evaluation. SuMoToRI was calibrated and evaluated with independent datasets from greenhouse experiments under contrasting S supply conditions. It is run with a small number of parameters with generic values, except in the case of the radiation use efficiency, which was shown to be modulated by S supply. The model gave satisfying predictions of the dynamics of growth, S allocation between compartments and S partitioning, such as the mobile-S fraction in the leaves, which is an indicator of the remobilization potential toward growing sinks. The mechanistic features of SuMoToRI provide a process-based framework that has enabled the description of the S remobilizing process in a species characterized by senescence during the vegetative phase. We believe that this model structure could be useful for modeling S dynamics in other arable crops that have similar senescence-related characteristics.
authors.affiliation: INRA, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France ; Normandie Université Caen, France ; UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Brunel-Muguet
authors.affiliation: INRA, UMR 1391 ISPA Villenave d'Ornon, France ; Bordeaux Sciences Agro, UMR 1391 ISPA Gradignan, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Mollier
authors.affiliation: UMR CNRS-UCBN 6139 Laboratoire de Mathématiques Nicolas Oresme, UFR des Sciences, Campus 2, Université de Caen Basse-Normandie Caen, France.
authors.forename: François
authors.initials: F
authors.lastname: Kauffmann
authors.affiliation: INRA, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France ; Normandie Université Caen, France ; UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Avice
authors.affiliation: INRA, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France ; Normandie Université Caen, France ; UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Goudier
authors.affiliation: INRA, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France ; Normandie Université Caen, France ; UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Sénécal
authors.affiliation: INRA, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France ; Normandie Université Caen, France ; UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et Nutritions N.C.S. Caen, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Etienne
keywords: model; oilseed rape; photosynthetically active radiation; sulfate; sulfur; temperature