Breeding with genetically modified plants

Abstract

Plant breeding aims at the genetic improvement of cultivated plants. Depending on the reproduction system of a plant the breeding process can last up to 15 years for crops and much longer for tree species. The breeding method is determined by the reproductive system of a plant and on the presence of hybrid yield (heterosis). Since the 1970s biotechnology is employed in plant breeding. The first genetically modified varieties came in the early 1990s. Although transgenic modification is only one among several other methods for increasing the genetic basis of plants it can create novel phenotypes not found among the gene pool of a plant species. Thus the constraints of classical breeding can be overcome by transgenic technology and a number of examples are presented where genetic variation has been substantially increased. In spite of this few varieties have been commercialized only from maize, soybean, rapeseed, cotton and papaya. The reasons are GMO legislation requiring strict separation of transgenic and non-transgenic seeds and agricultural commodities and the low acceptance of GMO products by food industry and consumers.