New targets in wheat improvement.

Climate change, expanding regional populations, changes in consumer preferences and improved technology will influence wheat breeding objectives in the coming decades. Traits that improve productivity in drier, warmer conditions are likely to become increasingly important and wheat cultivars with perennial habit, C<sub>4</sub> photosynthesis, improved nutrient use-efficiency and better adaptation to conservation agriculture could improve both the sustainability and productivity of wheat farming systems worldwide. The distribution of insects and diseases is expected to change in certain regions with implications for the deployment of resistance genes. The effectiveness of resistance genes may also change with temperature and CO<sub>2</sub> levels. Transgenes conferring immunity to some intractable diseases may offer longer-lasting solutions to disease infection and spread. The nutritional quality of both wholemeal and refined flour is expected to improve as more is understood of genetic variability for key micronutrients, their bioavailability and expression in different seed components. As markets become increasingly sophisticated, the demand for healthier foods will increase and wheat products with low glycaemic index or more antioxidants will be sought. The distribution of processed products worldwide may also change, as western societies increasingly favour wholemeal-based products and many developing countries replace rice-based diets with wheat as incomes improve. Wheat cultivars with strong, extensible dough and short mixing time have always been an important objective in western countries as longer mixing times reduce throughput. However, mixing time will take on an additional importance as energy costs continue to increase. As the proportion of meat increases in the diets of populations in transitional economies, the demand for grain for animal feed is also expected to continue to increase. Wheat cultivars with higher grain yield, improved digestibility and higher metabolizable energy, specific to monogastric and ruminant metabolisms, will be sought.