Oxidative Stress in Sugar Beet (Beta vulgaris L.) in Vitro Culture

Özet

The present study evaluated the effect of different sucrose concentrations in culture medium on explant growth, tissue necrosis and total phenolics content in leaf disc and petiole explants of two sugar beet (Beta vulgaris L.) cultivars (Kassandra and Visa) obtained from Sugar Research Institute, Etimesgut, Ankara. Leaf disc (1 cm2 containing mid vein) and petiole (0.7 cm in length) explants were excised from 8-week-old sterile seedlings and cultured for 5 weeks on MS medium supplemented with 0%, 1%, 2% and 3% (w/v) sucrose, 0.7% (w/v) agar, 1 mg l-1 BAP and 0.2mg l-1 NAA. Tissue necrosis on leaf disc and petiole explants was determined as mm2 by means of a computer program and a desktop scanner. First,total surface area of explants in mm2 per Petri dish was calculated. Then green parts were removed from the explant with a scalpel and the necrotic areas were measured by the same method. Finally, percent tissue necrosis was reported as the ratio of necrotic area to total explant area in a Petri dish. Total phenolics content was expressed as mg/100 g fresh tissue. According to the results, tissue necrosis decreased with decreasing sucrose concentrations in culture medium. The highest explant growth (total area, mm2) and the lowest tissue blackening was noted on the growth medium containing 1% sucrose.