PLANT-REGENERATION FROM SUGAR-BEET (BETA-VULGARIS L) HYPOCOTYLS CULTURED INVITRO AND FLOW CYTOMETRIC NUCLEAR-DNA ANALYSIS OF REGENERANTS

A simple and reproducible protocol for regeneration of sugarbeet plants from hypocotyl explants derived from 21 day-old-seedlings has been developed. Explants were cultured on MS medium containing 0.3 mg/l N6-Benzylaminopurine, 0.1 mg/l Naphthalene Acetic Acid, 50 mg/1 adenine and 0.5% (w/v) fructose, 0.5% (w/v) sucrose and 0.5% (w/v) glucose to induce the formation of organogenic calli (2.3% to 46.5% organogenic efficiency, depending on populations). Shoot formation was induced in callus cultures of more than 1600 genotypes. Physiological age affected culture response and different genotypes had different temperature optima for organogenesis. Following transfer of regenerated plants to the greenhouse, DNA determinations were made to study die stability of ploidy. Differences in ploidy were observed in plants derived from both short-term and long-term callus cultures; diploid true-to-type regenerants were 96% and 83%, respectively, from short-term and long-term callus cultures.