STUDIES ON THE EFFECTS OF GENOTYPIC VARIABILITY, SOURCE OF EXPLANT, AND CULTURE MEDIUM ON CALLUS GROWTH AND ORGANOGENIC CAPACITY OF Cucumis sativus L. PLANTS

Abstract

Cucumber (Cucumis sativus L.) is a native of Asia and Africa where it has been grown for food for at least 3000 years. It ranks sixth in total world tonnage of vegetable species production. As an important cucurbit, it is consumed in large quantities for both fresh fruit market and processed food industries throughout the world.

The increasing demand for cucumber as a key vegetable crop on local and international scale, extensive scientific knowledge on its culture, genetic, and physiology is required as a base-line resource for applying culture, and molecular biology technique in cucumber improvement.

The use of tissue culture techniques for rescue, maintenance, and propagation of cucumber genotypes • has been reported. Consequently, adventitious regeneration direct from explant tissue has been reported a number of times. On the other hand, researchers reported on the formation of somatic embryos in cucumber and remarkable progress has been made in its somatic embryogenesis. However, a low frequency of somatic embryogenesis is common in all published reports. Accordingly, we investigated in this study the influence of cultivar, explant source, and media components on the capacity of callus growth and potential of organogenic and embryogenic callus formation.