effect of salicylic acid on somatic embryogenesis and chlorogenic acid levels of carrot (daucus carota cv. nantes) explants

many factors may influence the efficiency of somatic embryogenesis. this capability may be differ with regard to media compositions, genotype, tissue, organ ontology and the stage of differentiation. the effects of five salicylic acid concentrations (0, 25, 50, 75 and 100 mm) on different stages of carrot somatic embryogenesis were studied using petiole and root secondary phloem explants as starting materials. the salicylic acid treatments were applied in two culture media; b5 and nl supplemented with 0.5 mgl-1 2, 4-dichlorophenoxy acetic acid (2, 4-d) and 1.0 mgl-1 indole-3-acetic acid (iaa), respectively. the chlorogenic acid (cga) levels produced by the explants during embryogenesis were monitored using high performance liquid chromatography (hplc) technique. the results proved that petioles are superior explants over root secondary phloems with regard to somatic embryogenesis. the b5 medium also exhibited induction of greater number of embryos over nl medium. the results of the present study unequivocally suggest that, irrespective of the type of explants and media culture, sa increments beyond than 75 mm negatively affect carrot somatic embryogenesis. a considerable elevation in cga production during embryogenesis following sa treatments was also found. chlorogenic acid produced by cultures was coincided with the sa treatments almost as the same manner that it affects somatic embryogenesis process. salicylic acid at the rate of 100 μm induced highest level of cga production and as result least number of embryos was formed.