Bioscience in brief
An introduction to genes and crops
Modern genetics and crop improvement
Modifying the genes of crops is the defining feature of the domestication of plants for agriculture. It has been practiced for thousands of years, and in its various forms, has provided us with all the crops we depend for our existence.
Two discoveries made it possible to understand the basis of how plants change through traditional breeding methods. The first of these was the discovery of the basic principles of genetics – the finding that what makes a species distinctive, and also each individual unique among all others, is the information locked in our genetic make-up. Each cell of the millions that compose an organism carries in long, folded strands of DNA-the blueprint of life, thousands of discrete information units, genes. It is genes that are the basis of heredity: we look like our parents because we have inherited our genes from them, and our children look like us because we passed on our genes to them. So, what our ancestors did unknowingly when they settled down to cultivate the land is to start a process of shuffling/combining genes between closely related plants which were capable of breeding with each other, and selecting the combinations that made better crops.
The second discovery was that the information encoded in genes is written in a universal language, the genetic code: all living organisms share it. This is the language of life. Modern molecular biology has made it possible to identify genes and to determine their function and role in crop improvement, thus aiding in the more rapid selection of the useful products of conventional cross breeding. It has also made it possible to isolate desirable genes from any organism, modify them, and reintroduce them into plants. Modern genetics has therefore provided tools to make conventional breeding more rapid and efficient, and also allowed breeders to increase variation within a crop beyond only being able to use populations of the same species and its close relatives.
Modern biotechnology is never a stand-alone solution – these tools need to be combined with conventional breeding techniques and good agricultural practices.