During last 20 years, crops of sunflower have extended throughout the developing countries due to its capacity to adapt to dry environments. Although a plant moderately tolerant of drought, production from this oil crop is strongly influenced by the presence of water stress which Is found fairly regularly

In fact, drought is a permanent feature in many developing countries and may also periodically influence the economies of Europe and the USA.

The threat from the trends in the global climate render this property ever more important.

At a scientific level there is a mass of work on the relationship between water supply and plant yield, but most deal with crops under irrigation. In contrast, useful knowledge concerning the improvement of the species to environments with trophic, especially water. limitations are still scarce and fragmentary. In our paper we have attempted to establish the state of the art of research into the strategies to adopt for improving drought resistance in sunflower, whilst trying to identify which of the many agronomic factors and physiological parameters may be used to improve the efficiency of selection processes.

In the establishment of a genetic improvement program aimed at improving the resistance to water stress, the following points must be included:

1) define the types of drought environment encountered in the target environment for each plant breeding program. because different types of drought may require different approaches.

2) describe plant "ideotypes" once the target environment is accurately defined.

3) determine which traits are to be considered to assist the development of drought-resistant cultivars.

4) given the particularly difficult conditions and unusual nature of drought-prone environments, accuracy is required in the identification of the selection method and the conduction of the experiment, in an attempt to steer the choice (identification of better progeny) towards data with a high number of replicates and not just single values.

5) analysis of data which allow the interpretation of the G x E interaction, in particular, when we are in the situation of identifying a single genotype which is ideal for various environments with different types of stress,

Only after having obtained all these information and having analysed them in a combined and/or separate manner for each type of environment. will it be possible to supply a concrete contribution to those who work daily in these difficult environments and to accelerate the provision of material which is truly tolerant to water stress in each environment. Finally, help must also come from molecular marker technology, because difficulties in identifying and conducting reliable drought-resistance screens can be overcome by improving the efficiency of selection for drought resistance via the use of molecular markers.