Experiments on the Isolation and Cultivation of Protoplasts and Calli from Agriculturally Important Plants II. Soybean (Glycine max L.) , )

Abstract

Summary Soybean callus has been cultured in a variety of ways on different defined media in an attempt to induce differentiation of formed organs and entire plants. To simulate the normally polar supply of auxin and cytokinin, some experiments were performed with divided petri plates containing differing concentrations and types of growth regulators in the separate compartments and also petri plates containing basal medium in which troughs were formed and filled with either auxin or cytokinin. In addition, media with varying cytokinin/auxin ratios and different kinds of cytokinin and auxin molecules were screened for organ-forming potential. The first two types of experiments induced growth regulator polarity in callus pieces, seen as altered callus morphology and altered isoperoxidase profiles, but no organization of roots or shoots occurred. Root induction occurred most frequently in the latter type of experiment on modified Gamborg B5 medium. Use of freshly induced stem and leaf callus exposed to varying media implicate thiamine concentration in conjunction with cytokinin/auxin ratio in root induction. Protoplasts have been isolated from callus tissue, stem segments and soybean embryos by treatment with 0.75% Driselase plus 0.75% Onozuka cellulase R10 in solid or liquid preparations. Leaf tissue exposed to the same conditions releases single cells but no protoplasts. Various media have been used for washing and culturing these protoplasts. Protoplasts have formed walls, but no divisions have been seen, despite prolonged culture.