Agronomy Research Expertise in Montpellier and Languedoc-Roussillon (South of France)

Agronomy : crops and cropping systems

Keywords :

Drought tolerance of maize crops: selecting genotypes for different agroclimatic conditions

4. Preserving water resources

4. Preserving water resources

From the phenotyping platform to the field: analysing genetic variability in the sensitivity of growth to water deficits and predicting the behaviour of genotypes under different agroclimatic conditions. © INRA - UMR LEPSE Improving drought tolerance in crops is hampered by the contradictory aims of maintaining production in drought conditions and reducing the yield loss risk. Depending on the climatic scenario, maintaining leaf growth under water shortage conditions may be an advantage (photosynthesis remains high) or a drawback (risk of plant death by faster soil water depletion). All genotype x climatic scenario combinations could be tested. The alternative being pursued combines experiments under controlled conditions with modelling to analyse genetic variability in adaptation traits and to predict its effect on yield.

Experiments are under way on maize lines whose allelic compositions have been determined using genetic markers. They are carried out within the PHENODYN phenotyping platform in which it is possible to measure—simultaneously in 400 plants—the transpiration and growth of leaves or reproductive organs, along with the water status of the soil and air, radiation and plant temperature. For studied functions, it is thus possible to quantify the effects of alleles on plant responses to environmental conditions—each genotype is characterized by a single set of response curve parameters. In collaboration with an Australian research team, the organ growth model was coupled with a biophysical model that simulates crop functioning on a plot scale. Based on real or virtual climate, soil and genotype data, the model calculates, on a daily time step, the water balance of the crop, biomass production and simulates the grain yield for each genotype and situation. An allele that promotes leaf growth can have a positive, negative or no effect on yield, depending on the climatic scenario. Combinations of the most interesting alleles for a given region can thus be determined.



Claude Welcker,
& François Tardieu,

Publication date: 30/05/2010



Update on 19/04/12


Extrait du site