Shoot organogenesis from cotyledon explants of watermelon
Watermelon, Citrullus lanatus Matsum and Nakai, is a frost tender, vining annual crop with sweet-tasting fruit that is often consumed as a cool desert. In light of both its importance and susceptibility to diseases, watermelon is an excellent candidate for improvement through genetic engineering. This chapter illustrates differences in shoot regeneration competence from different regions of cotyledon and among various watermelon cultivars. Use of the proper explants type is an important factor in successful organ regeneration. Not all explants from same plant or cotyledon possess equal regeneration potential. To develop an efficient plant regeneration protocol it is necessary to identify the best region of the plant from which to isolate explants. In watermelon the best explants source is the cotyledon of in vitro-germinated seedlings. In watermelon, most cultivars are competent for shoot regeneration from cotyledon explants. The chapter examines the ability of cotyledon explants from four watermelon cultivars to produce shoots. They are: 'Crimson Sweet', 'Minilee', 'Sangria', and 'Yellow Doll'.