2006 Volume 23 Issue 4 Pages 431-435
The effects of photoperiod, light intensity and gibberellic acid (GA3) on adventitious shoot regeneration from spinach cotyledons were tested. The Analysis of Variance F test showed that the effects of photoperiod and GA3 on shoot regeneration were significant at high light intensity of 90–100 μmol m−2 s−1. The combined effect of optimum shoot regeneration and highest shoot multiplication was observed in explants of short day (SD)-grown seedlings cultured under the SD condition and at high light intensity, with 0.5 mg l−1 GA3 in Murashige and Skoog medium supplemented with 1 mg l−1 6-benzyladenine and 0.4 mg l−1 α-naphthaleneacetic acid. Scanning electron microscopy observation revealed multiple shoots regenerating directly from the basal end of cotyledon preceding callus. The regenerated shoots developed into normal plantlets and grew well upon transfer to pots. Some regenerated shoots flowered in vitro under the non-inductive SD condition.
