High Frequency Direct Organogenesis in Five Romanian Tomato (Lycopersicon esculentum Mill.) Cultivars

Tomato (Lycopersicon esculentum Mill.) as the most economically important vegetable crop worldwide has been investigated intensively for the development of new and improved varieties. Most of these technologies require efficient protocols for in vitro regeneration and propagation of plant material. In the present study, an efficient and reproducible in vitro regeneration system for five Romanian tomato genotypes (cvs. ‘Capriciu’, ‘Darsirius’, ‘Kristin’, ‘Pontica’ and ‘Siriana’) has been established. The tomato genotypes were selected based on their horticultural and economically valuable traits. To study the in vitro morphogenic response, various explants, such as cotyledons, cotyledonary nodes, hypocotyls, leaf explants, internodes, stem nodes and apical buds have been selected. The highest efficiency in terms of direct shoot organogenesis was obtained in cv. ‘Capriciu’ (98% for apical buds and 94% for stem nodes) on culture media with zeatin and indole-3-butyric acid. One advantage of this regeneration procedure is beside its feasibility in handling, the high percentage of regenerated shoots and their rooting. The present protocol contributes to the existing information regarding the response of tomato cultivars to in vitro culture conditions.