Abstract:

Numerous research publications over the past 20 years have made it quite clear that a better understanding of the molecular and genetic basis for variation in root system architecture (RSA) will greatly aid the development of crop varieties with improved and more efficient nutrient and water acquisition under limiting conditions. In many parts of the world - especially in developing countries, food security is threatened by drought stress and poor soil fertility, which are major limitations to crop yields. These stresses are increasing in severity as climate change is resulting in more variable and extreme weather events (IPCC 4^th Assessment Report 2007). Furthermore, due to the rising costs for fertilizer production and distribution and increasing water scarcity, as well as the negative environmental impacts associated with overuse of fertilizers, further increases in crop yields via increased agricultural inputs are not sustainable nor are they economically viable in many developing countries (Lynch 2007). Thus, identifying how plants control the development of root system architecture canl have a real impact on improving agricultural food production and world food security in the 21^st century.