Calli were induced from the cuttings of test tube seedlings of Saposhnikovia divaricata (Turcz.)Schischk.cultured on MS medium containing 2,4 D 0.5 mg/L. After being transferred to a new medium without 2,4 D, the calli were put in the 160 kA/m magnetic field to induce embryogenesis. Magnetic field had no influence on the frequency of embryogenesis, but made the growth of the embryoids slower than control(PlateⅠ 6,7). It restrained the growth of cotyledon embryoids and shoot apex extension in small test tube seedlings, but accelerated growth of the roots, so resulted in seedlings looking like “todpoles”(PlateⅠ 10,11), which could develop into normal seedlings with better developed roots than those of the control group(PlateⅠ 9,12). The seedlings could be deformed when put in the magnetic field for a long time(PlateⅠ 13). Sub microscopic structural changes during the treatment were observed. It was noticed that the cell vacuolized rapidly, the electronic density of the cytoplasm became progressively lower, spherosome number decreased remarkably(PlateⅡ 2,4), the shape of cell nucleus changed and the chromatins seemed to be coacervating(PlateⅡ 5). But various cell organelles were still present.
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