DROPS

DROPS will develop novel methods and strategies aimed at yield maintenance under fluctuating water deficit and at enhanced plant water-use efficiency. We deal with high genotype x environment interaction in the field (any trait can have positive, negative or no effect depending on drought scenarios) with an approach combining Physiology, Genetics, field testing and Ecophysiological modelling. The project targets four traits : seed abortion, vegetative growth maintenance, root system architecture and transpiration efficiency. It deals with maize and durum wheat, plus bread wheat and sorghum for specific tasks. DROPS will: – Develop new screens for identifying drought tolerant genotypes, from phenotyping platforms to the field with indicators which are (i) stable characteristics of genotypes with high heritability in phenotyping platforms (ii) based on novel knowledge (e.g. combinations of metabolite concentrations, sensitivity parameters of models or hormonal balances) (iii) genetically related to target traits and able to predict genotype performance in the field via simulation and/or statistical models. – Explore the natural variation of the four target traits by (i) linking the target traits to physiological pathways, genes or genomic regions (ii) assessing the effects of a large allelic diversity for the four target traits via association genetics. – Support crop improvement strategies by developing methods for estimating the comparative advantages of relevant alleles and traits in fields with contrasting drought scenarios. This will be performed via field experiments and by developing a new generation of crop model able to estimate the effects of alleles on crop growth, yield and water-use efficiency Results and methods will be diffused (i) to breeders via the participation of seed companies and a partnership with a breeder association, (ii) to scientists and students via academic publications, and via practical courses and virtual courses in its website.

The EU-funded DROPS (Drought-tolerant yielding plants) project has developed new approaches to enhance water-use efficiency and improve yield in plants experiencing drought conditions. Researchers modelled plant performance in a range of environmental scenarios based on current and future climates. They used maize, durum wheat and bread wheat to investigate four traits: seed abortion rate, vegetative growth maintenance, root-system architecture and transpiration efficiency.

The natural variation of the four traits was explored in order to identify the regions in the genome that control them under a range of drought conditions and temperatures. The relevance of the involved ‘versions of genes’ (alleles) was tested in hundreds of climatic scenarios via crop modelling. This enabled identification of combination of alleles associated with better yields and water use efficiency in different regions of Europe, in current and future climate scenarios.

Simulations based on the hypothesis of an adaptation of crop cycle to climate change gave the unexpected result that, in well-watered conditions, climate change will have a limited impact on yield. Current simulations into the impact of climate change under the hypothesis that farmers will counteract the increased risk of heat and water stress by choosing adapted genotypes strongly suggest that this second source of adaptation also contributes to a lower impact of climate change.

Finally, a dedicated information system provided secure access to the entire DROPS dataset. It comprised a centralised database for phenotypic data collected in field experiments and web services that connect databases for genotypic, ′omic′ and phenotypic data collected in platforms.

The information system included tools for assessing the validity of phenotypic measurements and relating them to environmental variables. This enabled joint analysis of phenotypic data (field and platforms) together with environmental conditions and genotypic data for genetic analysis.

DROPs therefore provides both scientists and plant breeders with improved knowledge and tools to enhance crop plant water-use efficiency. It will help support crop improvement strategies through developing cultivars better able to withstand unfavourable climatic scenarios.