Project Details
Projekt
Integrating genetics into crop growth models to understand genotype response to combined (abiotic + biotic) stresses & synthesis of modelling (SP6)
Subject Area
Plant Cultivation, Plant Nutrition, Agricultural Technology
Term
since 2026
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 571153016
To date, no maize crop model explicitly links genetic information of different genotypes to ecophysiological parameters to quantify genotype performance under variable abiotic and biotic stress conditions. This limits the ability to understand and predict genotype-specific responses under increasing climate variability and extremes. This subproject addresses this gap by developing a novel, process-based modelling framework to quantify the effects and interactions of multiple stresses - specifically drought, nitrogen (N) deficiency, foliar disease, and stemborer herbivory - on maize productivity. The model will be applied to six temperate and six tropical commercia maize hybrids grown under contrasting environmental conditions. The project builds on existing robust modelling routines for simulating water and N dynamics. In the first step, these routines will be extended by incorporating new process-based routines to simulate combined effects of abiotic and biotic stressors. This enhanced model, referred to as the 'MultiStress model', will be calibrated and validated using detailed genotype-specific data from one tropical and one temperate hybrid. These steps ensure the model accurately represents physiological responses to complex, interacting stress factors under field conditions. The next step involves establishing quantitative relationships between genotype-specific information and key crop model parameters. Traits of interest include flowering time, transpiration efficiency, disease susceptibility, and pest resistance. These relationships will be validated by testing whether they enable accurate parameterization of all remaining genotypes and meaningful differentiation of physiological performance across diverse environments. Once fully parameterized, the MultiStress model will be used to test two central hypotheses: (1) the effects of multiple abiotic and biotic stressors are non-additive, and (2) the severity of combined stress effects is greater in tropical than in temperate environments; we attribute this to the fact that tropical growing conditions are characterized by higher temperatures and humidity, faster phenological development, and more intense pest and disease pressure. Genotype-specific simulations will be conducted across stress scenarios to evaluate interactions and crop performance. In the final step, the MultiStress model will be used to identify promising genetic trait combinations for different environmental stress conditions. This integrated approach will generate novel mechanistic insights into field-level performance of maize genotypes under concurrent multiple stress conditions. By directly linking genotype characteristics to crop model parameters, the MultiStress framework will bridge genetics and ecophysiology to support improved breeding and management strategies in temperate and tropical maize systems under concomitant stress conditions.
DFG Programme
Research Units
