干旱区生态环境知识资源中心

A review is presented of crop physiological adaptation and benefits associated with deficit and variable water conditions. It is widely accepted that ABA mediates general adaptive responses to drought. However, there is evidence suggesting that additional signals are involved in this process. Breeding of drought resistance shows that a high yield potential is negatively associated with certain drought adaptive traits in wheat. Such a negative association may put a limit on raising potential yield as means for improving actual yield under semiarid conditions. For a relatively determinate target stress environment and with stable genotype X environment interaction, the probability for achieving progress is high. This approach will be possible only after we learn more about the physiology and genetics,of wheat plant responses to water stress and their interaction s The difficulties encountered by molecular biologists in at tempting to improve crop drought resistance are due to our ignorance in agronomy and crop physiology and not to lack of knowledge or technical expertise in molecular biology.