Aseptic culture techniques have figured prominently in the study of plant growth and development. The identity of hormones and role of growth regulators came about in large measure as a result of these studies. The first successful aseptic cultures were those of excised root tips. Somewhat later it became possible to grow callus cultures derived from storage organ explants or the cambial region of woody species. These cultures grew slowly and the stimuli to cell division usually entailed the addition of auxins such as indole-3-acetic acid (IAA) or naphthaleneacetic acid (NAA) to otherwise simple media comprised of mineral salts, sucrose and a few vitamins (16).