Effect of various factors on shoot regeneration from citrus epicotyl explants

Abstract: The effect of various treatments on shoot organogenesis from seedling epicotyl explants from various scion and rootstock polyembryonic citrus types was determined. Treatments included water source, gelling agent, explant insertion, seed size, light intensity, malachite green, nonionic surfactants, and sodium sulphate. Tap water, with the highest levels of SO42-, Ca2+, K+, Mg2+, and Na+, resulted in the most shoots compared to the other 5 sources, suggesting a mineral nutrient effect. Carrageenan produced fewer shoots than agar and gellan gum. Explants inserted into the medium produced more shoots than those cultured on the surface, presumably because of better exposure to water and nutrients. Seed size, light intensity, malachite green, and sodium sulphate had no effect on the number of shoots regenerated. Triton X-100 at 0.1 % resulted in significantly fewer shoots; otherwise, nonionic surfactants had no effect.