THE CURRENT STATUS OF KNOWLEDGE ON THE CELLULAR BIOLOGY OF POTATO

Conventional potato breeding does not make full use of the existing bi odiversity within the Solanum genus. Moreover breeding at the 4x-4x le vel is slow. The potential for breeding at the diploid and dihaploid l evels has therefore been explored. This requires use of novel techniqu es to overcome deviations from the desired Endosperm Balance Number. S omatic hybridization approaches include symmetric and asymmetric hybri dizations and cybridization. Interesting traits have been successfully transferred through these techniques. Introgression and chromosome el imination have profited from the recent and rapid development of analy tical techniques such as RFLP and RAPD. Cellular approaches in potato breeding may be combined with conventional breeding by a stepwise redu ction of the ploidy level followed by resynthesis of a new heterozygou s tetraploid clone. Such schemes have been used to include virus or ne matode resistance. Haploids may be derived from different sources or o btained through different techniques. Dihaploid-dihaploid breeding pro grammes may be especially interesting. Because of this potential, cell ular biology of potato deserves the continued interest of the scientif ic community.