New Biological Approaches for Agriculture

The origin and the progress of agriculture have relied since its beginning in the Neolithic era in the application of the best available knowledge. Plant domestication involved the identification of a limited number of plant and animal species and a narrow range of variation within the species that allowed their cultivation. Starting at the end of 18 century the recognition of how important agronomic characters are transmitted gave rise to the science of genetics that was systematically applied during the last century. Recombinant DNA technologies are presently making an important impact in the breeding of new cultivars by the use of marker assisted selection and the use of genetic transgenesis. With the advent of massive sequencing and genotyping we are witnessing the appearance of a new dimension in our knowledge of the genetic and molecular basis of the characters that are important for crop improvement. All these developments are having a large impact in how research is being carried out. We are immersed in a new complexity that exists at the global level with both industrial and social consequences. THE DEVELOPMENT OF AGRICULTURE The development of agriculture has historically been based in the identification of a reduced number of species that have the appropriate features to be cultivated. From several international reports it can be concluded that out of approximately 500,000 species of flowering plants, around 30,000 of them might have something edible, and around 4000 have been considered as cultivated crops (Sanchez-Monge, 1992) at some period of the evolution of human societies. However at this moment only 120 plant species are important for local communities of which 30 provide 90% of the calories that people use for their living. Three main cereals: wheat, rice and maize, provide about 50% of the energy we obtain from plants. Agriculture is one of the founding steps of human civilization and plant and animal domestication are essential requirements for its development. The extraordinary discovery, between 10,000 and 50,000 years ago, of a few species or plants and animals that might be cultivated or domesticated indicates a patient wisdom of identification of plant and animal populations and individuals that have unique properties to produce food and other materials. This discovery permitted a complex Neolithic society to survive. We know now that these properties correspond to genetic variants that are only present in a small number of species. The analysis of these properties by the use of molecular methods (Salamini et al., 2002; Doebley, 2004; Li et al., 2006) is allowing the retracing of complex pathway that led to agriculture. This new production of food but also of feed and fibre became efficient enough to allow that a significant proportion of societies may be devoted to activities other that hunting and gathering. When the period of long maritime travels