EcoMeristem, a model of morphogenesis and competition among sinks in rice : 1. concept, validation and sensitivity analysis

Luquet Delphine, Dingkuhn Michaël, Kim Hae Koo, Tambour Ludovic, Clément-Vidal Anne. 2006. EcoMeristem, a model of morphogenesis and competition among sinks in rice : 1. concept, validation and sensitivity analysis. Functional Plant Biology, 33 (4) : 309-323.

Résumé : Because of rapid advances in functional genomics there is an increasing demand for models simulating complex traits, such as the physiological and environmental controls of plant morphology. This paper describes, validates and explores the behaviour of the structural-functional model EcoMeristem, developed for cereals in the context of the Generation Challenge Program (GCP; CGIAR). EcoMeristem constructs the plant on the basis of an organogenetic body plan, driven by intrinsic (genetic) behavioural norms of meristems. These norms consist of phenological-topological rules for organ initiation and pre-dimensioning (sink creation) and rules enabling feedbacks of the plant's resource status on the organogenetic processes. Plant resource status is expressed by a state variable called Internal Competition Index (Ic) calculated daily as the ratio of assimilate source (supply) over the sum of active sinks (demand). Ic constitutes an internal signal analogous to sugar signalling. Ic affects potential phytomer size, tiller initiation, leaf senescence, and carbohydrate storage and mobilisation. The model was calibrated and tested on IR64 rice grown in controlled environments, and validated with field observations for the same cultivar (Philippines). Observed distributions and dynamics of soluble sugars and starch in plant organs supported the model concepts of internal competition and the role of reserves as a buffer for lc fluctuations. Model sensitivity analyses suggested that plant growth and development depend not only on assimilate supply, but also on organogenesis-based demand. If true, this conclusion has important consequences for crop improvement strategies.

Mots-clés Agrovoc : Oryza sativa, morphogénèse, organogénèse, développement biologique, phénotype, port de la plante, modèle de simulation, modèle mathématique, croissance, besoin nutritionnel, offre et demande

Mots-clés complémentaires : Biomodélisation, Sink effect

Classification Agris : F62 - Physiologie végétale - Croissance et développement
U10 - Informatique, mathématiques et statistiques

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Luquet Delphine, CIRAD-AMIS-UPR Modélisation intégrative (FRA) ORCID: 0000-0002-2543-7140
• Dingkuhn Michaël, CIRAD-AMIS-UPR Modélisation intégrative (FRA)
• Kim Hae Koo, CIRAD-AMIS-UPR Modélisation intégrative (FRA)
• Tambour Ludovic, CIRAD-AMIS-UPR Modélisation intégrative (FRA)
• Clément-Vidal Anne, CIRAD-AMIS-UPR Modélisation intégrative (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/532468/)

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