Imidacloprid is a systematic neonicotinoid widely used to combat piercing-sucking insects; however, neonicotinoids, despite having low effects on vertebrates, showed high adverse effects on honeybees (Apis mellifera L.). Glutathione-S-transferases (GST) are an important constituent of the defense system in detoxifying invading chemicals. This work examines the effects of imidacloprid on GST activity in vivo and in vitro conditions. Results revealed that there are two responses of GST activity toward IMI treatment; first, stimulation of enzyme activity to combat and detoxify the insecticide. Second, direct inhibition of GST, which is confirmed by the in vitro inhibition with IC50 887.42 ppm. At a short exposure time to IMI (2 hours) at an IMI concentration of 0.35 ppm, the enzyme was stimulated up to 113% while increasing exposure time or IMI concentration, the inhibition effect dominates.

This study was achieved at the Tissue Culture Laboratory of the Agricultural Genetic Engineering Research Institute, Giza, Egypt during the period from 2013 to 2017, Direct embryo initiation and callus formation of date palm cv. Sewi from immature female inflorescences have been achieved on modified MS medium supplemented with 4 mg l-1 Picloram plus 3 mg l-1 2 iP and 2 g l-1 PVP. Results also showed that BA at 0.5 mg l-1 produce the highest number of differentiated embryos/culture, while kinetin at 0.25 mg l-1 significantly increased the average number of adventitious shoots/culture. NAA at 1.0 mg l-1 induced the highest rooting percentage and micro-shoot length. On the other hand the best survival percentage during the acclimatization stage was observed with plantlets produced from IBA at 0.5 mg l-1 during the rooting stage.