A study on effects of plant growth regulators on the morphogenesis of Hibiscus sagittifolius Kurz under in vitro conditions
Keywords:Hibiscus sagittifolius, growth regulators, germination, morphogenesis.
Hibiscus sagittifolius Kurz is an important herbal medicine that belongs to the Malvaceae family. However, the number of this plant in the nature has been decreasing dramatically because of its narrow distribution, overexploitation and low germination of seeds. Our study focused on investigating the effects of plant growth regulators on germination of seeds, formation of shoots and roots of this species under in vitro conditions. In our study, after 45 days of culture, the germination rate was the highest (55.6%) when seeds were soaked in 30 mg/l GA3 solution within 120 minutes, then sterilized with 0.5% HgCl2 solution, finally transferred to MS medium supplemented with 10 mg/l GA3. After 30 days of culture, shoot multiplication rate of yellow, red and pink varieties made from nodes was the highest (4.5 shoots/explant) when explants were cultured on MS medium supplemented with 1 mg/l BA, 10% coconut water, 0.2 mg/l GA3. After 30 days of culture, in vitro shoots produced adventitious roots and grew best (6.6 roots/shoot and length of 10.5 cm/ bud) when being grown on MS medium supplemented with 0.5 mg/l IBA and 0.5 mg.l-1 NAA. Thus, the method of tissue culture can produce a large number of Hibiscus sagittifolius in a short time.