PRESENT STATE AND FUTURE-PROSPECTS OF BIOTECHNOLOGY IN SUNFLOWER BREEDING

The cultivated sunflower is considered to be a species very recalcitrant to various methods of biotechnology, although substantial progress has been made in recent years. For example, very efficient embryo culture techniques are available for obtaining numerous wide crosses which can be very valuable for broadening genetic variation in sunflower. In particular, interspecific hybrids have been demonstrated to be a unique source for creating "new" traits, like cytoplasmic male sterility (CMS) or resistance against devastating diseases, such as Sclerotinia rot. The successful regeneration of entire plants from cultured somatic tissue or even single cells, i.e. protoplasts, has been demonstrated for specific genotypes. Furthermore, the recovery of androgenetic haploid and doubled haploid plants is basically feasible in sunflower, although the rate of regeneration strongly depends on genotype. Particular progress has been made in the field of "genome characterization" , by using both biochemical and molecular markers. In particular, the chloroplast and mitochondrial genomes have been analyzed and described in detail. Such analyses built the foundation for future "marker-based selection" and for the identification and isolation of specific genes as candidates for "genetic engineering".