Generally excised root is cultured in liquid medium. It has several advantages over solid media. The techniques of root culture give certain important informations such as : (i)
nutritional requirements, (ii)
infection by Rhizobium
and nodulation, and (iii)
physiological activities, for example, production of alkaloids, nicotine, etc. (Dodds and Roberts, 1985). For the first time White (1934) reported the successful organ culture e.g.
potentially unlimited growth of excised tomato roots. Subsequently, roots of several species of gymnosperms and angiosperms have been successfully cultured.