Due to its tetraploid and highly heterozygous genome and the tetrasomic inheritance potato genetics is very complex. Thus the development of new cultivars employs combinational breeding. Cultivars and breeding clones are crossed aiming at the combination of optimal characteristics. The breeding process of 10 years involves a sexual propagation in the first year (crossing) and 9 years of vegetative propagation during which several characteristics are selected for.
	In potato breeding the main source of alleles is the pool of existing cultivars. Nevertheless the nowadays cultivars originate in a few introductions of potatoes from South America making the diversity of alleles somewhat narrow. To enlarge this there are continuous efforts to use wild species for the introduction of new alleles and genes. Employment of wild species results not only in the introduction of needed alleles and wanted traits but instead also unwanted traits are transferred in parallel. To get rid of unwanted genes/alleles additional breeding steps are needed resulting in breeding horizons of several decades. Hence it is appreciable that new alleles are generated directly within the genomes of elite clones by this generating a new source of allelic variation which may be employed directly for the breeding of high quality cultivars. This would keep breeding horizons within the known time scales.
Aiming at this EMS-mutagenesis combined with a technology to detect single-nucleotide differences represents a useful tool. Chemical mutagenesis with agents like ethylmethanesulfonate (EMS) has the advantage that predominantly point mutations are generated at a high mutation densitiy. Transitions (G/C to A/T) may result in modified triplets coding for new amino acid, stop codons can be generated or splice sites may be lost.
	This project aims at comparing the efficiency of employing different ploidy levels of the mutagenized material (diploid and tetraploid breeding clones) and methodologies for mutation detection (high throughput sequencing and mismatch detection by using single strand specific nucleases).

Project partners

BIOPLANT Biotechnologisches Forschungslabor GmbH
Fraunhofer-Institut für Molekularbiologie und Angewandte Ökologie
Universität Potsdam

Last Updated ( Wednesday, 09 January 2008 )