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.
Photosynthetic and growth characteristics of the control potato plants cv. Zvíkov and those transformed by Agrobacterium were compared during their cultivation in vitro in agar medium with 1 % saccharose, after having been transplanted into pots with soil, or growing from tubers in soil. The average leaf aiea, fresh and dry matter, chlorophyll a and b ratio, and contents calculated per fresh and diy matter of the leaf area were significantly higher in the control plants raised from tubers and in vitro cultivated than in the transplanted ones. The significant increase in oxygen evolution by leaf fragments was found only in the control potato plants raised from tubers. Differences between photochemical activities of chloroplasts isolated from control and transformed plants were statistically significant only when calculated per fresh leaf matter. Chloroplasts from transformed potato plants grown from tubers and from those cultivated in vitro exhibited higher activities of photosystems (PS) 2 and PS 1 independently on the donors and acceptors of electrons ušed. On the contrary, higher activities of both photosystems were found in chloroplasts isolated from the control plants transferred to soil.