DROPS develops novel methods and strategies aimed at improving yield under fluctuating water deficits and at enhancing plant water-use efficiency. We deal with the high genotype x environment interaction in the field (any trait or allele can have positive, negative or no effect depending on drought scenarios) with an approach based on recent progress in phenotyping methods, physiological knowledge, genetic approaches and modelling.
The project comprises three main components :
- design, development and use of novel phenotypic methods in the field as well as in phenotyping platforms, with the aid of model-assisted data analysis,
- identification of polymorphisms in genes or regulatory regions associated with traits involved in drought tolerance and water-use efficiency, and analysis of the effects of allelic diversity on these traits,
- development of methods to assess the comparative advantages of traits and alleles in various drought scenarios, based on a network of field experiments and on the development of simulation modelling.
The project targets four traits :
- seed abortion,
- vegetative growth maintenance,
- root system architecture and,
- transpiration efficiency.
Maize (9 M Ha in EU) and durum wheat (3 M Ha in EU) are major crops for which drought already poses a crucial problem :
- They have an economic relevance and are facing high risk of water deficit in current of future European climates
- They allow rapid progress because of existing genetic, genomic and physiological knowledge
- They are sufficiently close to each other to allow comparative biology and synteny analyses
European agriculture is facing declining water availability, a reduction of arable land and strongly increasing demand for cereals. Predictions of climate change indicate an increased variability of rainfall in the next 40 years and an increased risk of high temperature and of water shortage during summers. It is increasingly accepted that these events will jeopardize global food security unless large adaptation investments are made. Socio-economic projections suggest an increased demand for cereals (65% in the next 20 years), which has resulted in large fluctuations of the price of cereals over the last two years. Meanwhile, water for irrigation will be at best maintained at current levels though at higher cost. New genotypes are therefore needed to at least maintain levels of productivity with reduced water input. This is a challenge for the society, but also for the competitiveness of European seed companies since Monsanto has submitted to the FDA a new drought tolerant maize genotype in December 2008.
During the last decade, most academic effort has been devoted to identification of single genes that would confer drought tolerance, via mechanisms as different as overproduction of growth regulators, tolerance to oxidative stress, changes in metabolic pathways or manipulation of transcription factors. This has resulted in spectacular results in specific, usually controlled, conditions. However, no application has followed yet these results in the development of improved genotypes, except the Monsanto's submission. Holistic approaches aimed to explore and manipulate the natural variation of key productivity traits have been more efficient with, for example, the release of varieties of wheat with improved water-use efficiency or maize with improved tolerance to water deficit.
The pace of genetic progress must now accelerated by alleviating four bottlenecks.
- Phenotyping, which is lagging behind genetic and genomic progress.
- Novel genetic approaches such as Whole-genome association mapping have essentially dealt with simple phenotypic traits. We aim to use it for drought tolerance, with an application in genomic selection.
- Genotypic and phenotypic data gererate huge datasets which have to be organised in databases and analysed with relevant methods, based on statistics and modelling.
- Modelling the effect of allelic variability is essential because the agronomic value of an allele or trait varies with the drought scenario.
This project is supported by the European Commission under the