9 9 Genetics and Reproductive Biology of Cultivated Potato (Solanum tuberosum L.): Implications in Breeding Jane Muthoni, 1,2, * Hussein Shimelis 1 and Rob Melis 1 ABSTRACT This article gives an overview of potato genetics and reproductive biology and their implication in conventional potato breeding. The commonly cultivated potato (Solanum tuberosum ssp. tuberosum L.) is an autotetraploid (2n=4x=48, 4EBN) with tetrasomic inheritance. Both interlocus (epistasis) and intralocus (heterozygosity) interactions occur and the more they are, the greater the heterosis. Favourable traits are fixed in F 1 generation due to clonal propagation. Potato exhibits inbreeding depression characteristic to cross pollinated species yet most of the seeds obtained from open-pollinated fruits are the result of self fertilization; flowering and fruiting are mainly affected by 1 African Centre for Crop Improvement, University of KwaZulu-Natal. Private Bag X01, Scottsxille 3209, Pietermaritzburg, South Africa. Emails: Shimelish@ukzn.ac.za; melisr@ukzn.ac.za 2 Kenya Agricultural Research Institute (KARI). National Potato Research Centre, Tigoni. Kenya. * Corresponding author: jayney480@yahoo.com List of abbreviations after the text.