The current status of knowledge on the cellular biology of potato

Summary Conventional potato breeding does not make full use of the existing biodiversity within theSolanum genus. Moreover breeding at the 4x-4x level is slow. The potential for breeding at the diploid and dihaploid levels has therefore been explored. This requires use of novel techniques to overcome deviations from the desired Endosperm Balance Number. Somatic hybridization approaches include symmetric and asymmetric hybridizations and cybridization. Interesting traits have been successfully transferred through these techniques. Introgression and chromosome elimination have profited from the recent and rapid development of analytical techniques such as RFLP and RAPD. Cellular approaches in potato breeding may be combined with conventional breeding by a stepwise reduction of the ploidy level followed by resynthesis of a new heterozygous tetraploid clone. Such schemes have been used to include virus or nematode resistance. Haploids may be derived from different sources or obtained through different techniques. Dihaploid-dihaploid breeding programmes may be especially interesting. Because of this potential, cellular biology of potato deserves the continued interest of the scientific community.