Physiological studies on micropropagation of some date palm cultivars: 2. Some hormonal and chemical changes via embryogenesis and germination.

摘要

Hormonal and chemical changes during embryogenesis and germination of 3 dry date palm cultivars in vitro were studied. Shoot tip explants from cultivars Bartamuda, Gondila and Shamia were used. Samples were taken from various stages of micropropagation for the analysis of IAA, GA3 [gibberellic acid], zeatin, ABA [abscisic acid], total soluble sugars, free amino acids and proline. The contents of IAA and GA3 in shoot tip explants increased to peak levels, decreased at the embryo stage, then increased from the embryo stage to the germinated embryo stage. The zeatin content was highest at the embryogenic callus stage. The ABA content at the callus stage maintained a relatively high level, but the contents of IAA, GA3 and ABA decreased to the lowest levels at the embryo stage. Shoot tip explants of Bartamuda had the highest levels of IAA and GA3. The highest level of zeatin was observed at the embryogenic callus stage, but the highest level of ABA was detected at the callus stage. Gondila had the highest zeatin content, while Shamia had the highest ABA content. The callus stage recorded the highest total soluble sugar content. The free amino acid content was highest at the germinated embryo and shoot tip stages. The highest concentration of free amino acids content was observed at the germinated embryo stage. The shoot tip, embryo and germinated embryo stages registered the highest proline contents. The highest proline content was recorded for Bartamuda shoot tip explant. Bartamuda had the highest contents of total soluble sugars and proline. Shamia had the highest concentration of proline, while Shamia and Gondila had the highest concentration of free amino acids. Bartamuda had the highest contents of total soluble sugars at the shoot tip and callus stages, while Shamia had the highest content of total soluble sugars at the callus stage. The highest concentration of free amino acids was detected at the germinated embryo and shoot tip stages. Bartamuda had the highest proline content at the shoot tip and germinated embryo stages..