ABSTRACT
Most of the sunflower (Helianthus annuus L.) plants cultivated worldwide are grown for their seeds, which are rich in oil and protein. Although a small proportion of the production is directly consumed in the form of grains, e.g., as a snack or birdfeed, the largest part is processed to yield a highly appreciated oil with a balanced composition of fatty acids and good nutritious value. In several countries, sunflower oil is the exclusive source of vegetable oil; on a worldwide scale, it is among the four most important species cultivated as oil crops. This leading position has been made possible by a very successful application of conventional breeding. The introduction of high-performing F1 hybrids, based on the cytoplasmic male sterility (CMS) system developed in 1969 by Leclercq (1), has promoted very fast development of this crop. The economic importance of sunflower has stimulated interest in the development of biotechnological approaches, which are hoped to extend the possibilities for further improvement of this crop. Simple conventional in vitro techniques are already applied with good results; the acceleration of the growth cycle by embryo culture, which allows the production of up to five generations per year, is a good example. However, the potential impact of genetic engineering is estimated to exceed greatly that of conventional techniques. The transfer of isolated and well-characterized genes is expected to confer novel traits that would otherwise remain inaccessible on this important crop.
