IN VITRO LIQUID CULTURE OF Stevia rebaudiana Bert. FOR MASS PROPAGATION

Abstract

Stevia leaves are important as a new source of natural sugar substitute which makes it one of the most valuable new crops for Europe. The development of in vitro vegetative propagation strategies, to secure availability of well characterised and healthy clonal accession of plant material capable of providing an economically accepted level of leaf and stevioside harvest, becomes an agricultural priority. Growth and development of new plantles were strongly influenced by the type of in vitro plant support and by the presence of exogenous plant growth regulators added to the medium, the best combination was that of auxin (IBA 0.5 mg/l) and cytokinin (Kin 0.2 mg/l). The sponge-like structure of the fruits of Luffa cylindrica were used as plant support for liquid media. Results confirm that an in vitro multiplication of plant material is a reliable system for mass production of seedling to be cultivated in the field condition. The liquid system allows a superior root system formation. The use of Luffa cylindrica for ex vitro transfer proved to be a technological like approach, the ligno-skeleton cube replacing the usual giffy-pot system.