TRANSFORMATION OF DIPLOID POTATO WITH AN AGROBACTERIUM-TUMEFACIENS BINARY VECTOR SYSTEM .2. STABILITY OF TRANSFORMATION IN TUBERS, MICROPROPAGATED AND GREENHOUSE-GROWN PLANTS

Stability of neomycin phosphotransferase (NPTII) and beta-glucuronidas e (GUS) genes expression in transformed dihaploid H8105 potato plants was studied. GUS activity and resistance to kanamycin (conferred by NP TII expression) were estimated during over two years period of vegetat ive plant propagation, both in vitro and in vivo. The experiments were performed with plants grown in vitro (micropropagated, minitubers, ce ll suspension culture), as well as in greenhouse conditions (whole pla nts, part of plants, tubers). The activity of GUS enzyme was stable du ring the experimental period, except for minitubers and normal tubers, which showed several times lower GUS activity. The activity in stems was higher than in leaves and roots. The resistance of transgenes to k anamycin was also preserved. Transformation of dihaploid potato did no t affect the morphology and development of transgenic plants.