Abstract:
A study of factors affecting morphogenesis by Ornithogalum 'Rollow' and Ornithoyalum maculatum explants was made to facilitate the rapid multiplication of products of the breeding programme of the Vegetable and Ornamental Plant Research Institute in South Africa. The water potential of Nel's (1981) medium declined insufficiently over the culture period to constitute a physical stress on explants. The inclusion of agar and a citrate - K2HPo4 buffer system lowered the water potential of the culture medium significantly. Where the medium was buffered, quadratic relationship existed between medium water potential and pH. During culture, most nutrients were utilized between pH 5.6 and pll 6.5. The buffering Capacity of the culture medium was minimal between pH 3,0 and pH 8. Neither the addition of phytohormones to the medium, nor autoclaving significantly affected the buffering capacity of the medium.
