Charactenstícs of the pigment apparatus were studied in plants grown from tubers of the oř 3’’^ doně generation of two cultivars of potato (Solanum tuberosum L) transformed with Agrobacterium tumefaciens strains. The cv. Zvíkov carries pRiA4b T-DNA of A. rhizogenes and the vector plasmid pGA472 T-DNA carrying the gene for kanamycin resistance. The cv. Kamýk carries the vector plasmid pCB1339 which contains the kanamycin resistance gene and the cytokinin synthesis gene. In the field experiments, the plant dry matter, the relative water content, the chlorophyll (Chl) a and b contents, the Chl a/b ratio and the course of slow Chl fluorescence induction curves were not signifícantly different in transformed and control plants. The amoímt of the Chl-protein complexes of the reaction centres of both photosystems separated by electrophoresis was similar for both transformed and control plants. Howevér, the content of oligomeric light-harvesting complex was significantly higher in both the transformants.