Nutrient factors affecting in vitro cultivation of Stevia rebaudiana

Abstract

The present work was carried out to display in details the whole protocol for Stevia rebaudiana propagation through tissue culture techniques to produce and introduce Stevia rebaudiana plants as a new sweetener crop to Egyptian agriculture. In order to maximize plant propagation efficiently via direct organogenesis, it is important to study the influence of plant nutrient medium and its components at different levels. The study included the effect of MS salt strength and major elements containing medium at different levels on the in vitro growth and development of Stevia rebaudiana The best nutrient medium was MS at full salt strength or modified MS major elements at these levels (NH₄NO₃ at 1237.5 mg/l, KNO₃ at 950 mg /l, MgSO₄ at 185 mg/l, CaCl₂.2H₂O at 440 Mg/l and KH₂PO₄ at 85 mg/l) and minor elements supplemented with 30 g/l sucrose, 2 mg/l glycine, 0.5 mg/l pyrodoxine, 0.5 mg/l nicotinic acid, 0.1 mg /l thiamine and solidified with 1.5 g/l agar + 1.5 g/l gelrite. The ex vitro plantlets were successfully acclimatized in planting medium containing peat, sand and vermoculite at equal volume. Hardening plants were cultivated under Sadat soil conditions (10 volume sand + 3 volume loam) which achieved good growth and these plants used as a source of vegetative propagation after 50 days by using terminal cuttings.