What are the prospects for genetic improvement of drought-tolerant cultivated plants?
The objective of this study is to establish an inventory of research and the dissemination of cultivated plants with a potential for adaptation to drought greater than current varieties. Indeed, drought, a current environmental constraint, also risks being one of the major consequences of climate change.
The working method consisted of two main stages. First, a literature review, then surveys of laboratories in public research organizations and private companies. These surveys took place in France and more broadly in Europe, as well as in the United States and Kenya. Therefore, the results reflect the bulk of the work underway in France, the United States, and Africa. The study prioritized cereals grown in both developed and developing countries (maize, wheat, rice, sorghum, and millet), and examined the different research perspectives implemented for plant breeding, both conventional breeding and transgenesis.
Two maize varieties with improved drought tolerance will soon be marketed in the United States, where demand from farmers is high. One, conventional, is the result of a traditional breeding process, the other of transgenesis. Although these varieties are aimed at the North American market, this research could benefit African agriculture, since an international program bringing together seed companies, national and international public research, and American foundations was launched a few years ago to transfer advances made in maize to tropical species.
This analysis shows that, while progress made over the past thirty years in plant biology has made it possible to accelerate, target, and facilitate selection processes, genetic resources remain the keystone of breeding programs. It also shows that this progress depends on economic and biological criteria related to the species in question. Thus, maize currently accounts for a large portion of private research investment in improving drought tolerance. It is also important to note that since drought tolerance relies on complex biological processes, research continues, and the road ahead is long. Finally, exploiting the potential of improved seeds cannot be achieved without joint improvement of associated agronomic practices and the funding they require—particularly in developing countries.
