Single node and multinode explants of two potato cvs., Desiree and Cardinal were tested for in vitro microtuber production. Explants were taken from tissue culture laboratory of Seed Centre, University of the Punjab, Lahore, Pakistan in 2004. Experiments were designed in completely randomized pattern. 34 media treatments of Murashige and Skoog (1962) with varying concentrations of sucrose (4, 6, 8, 10 and 12%) either alone or in combination (5-8% sucrose) with 6-benzyl amino purine (BA) were studied. In the case of cv. Desiree, medium MB10 (BA 6 mg/l, sucrose 6%) and for cv. Cardinal, medium MK20 (BA 5 mg/l, sucrose 8%) in term of induction, mean number and mean fresh weight per single node explant were optimized. In comparison, cv. Desiree genotypically was observed to be slightly slow in response to in vitro microtuber induction and development than cv. Cardinal.

Key words: Potato, microtuberproduction, 6-benzyl aminopurine (BA), sucrose.