Abstract

This research was carried out at the Plant Tissue Culture Laboratory – Center of Desert Studies – Anbar of University to study the effect of some growth regulators on the induction of callus from the hypocotyl of plant Cucurbita pepo var.styriaca. These regulators included 2,4-D (Dichlorophenoxyacetic acid) at a concentration of (0.0, 1.0, 2.0 and 3.0) mg l-1 and cytokinin BA (Benzyl adenine) at a concentration of (0.0, 0.5, 1.0 and 2.0) mg l-1. Cytokinin TDZ (Thidiazuron) with a concentration of (0.00, 0.01, 0.05 and 0.10) mg l-1 was used and interfered with by the 2,4-D. The results showed that the medium MS supplemented with a concentration of 1.0 mg 2,4-D l-1 gave the highest response rate for callus induction from the hypocotyl at 87.5%, while the concentration gave 1.0 mg BA l-1 the highest induction rate of 92.5%,the interaction between 2.0 mg 2,4-D l-1 and 1.0 mg BA l-1 recorded the fresh weight and dry weight of 225.80 and 23.34 mg respectively. As for the effect of 2,4-D with TDZ, the interaction between concentration 0.0 mg 2,4-D l-1 and 0.10 mg TDZ l-1 gave the highest induction ratio, fresh and dry weight of callus 100%, 306.64 and 30.0 mg, respectively.