Research Article: Extraction of abscisic acid and gibberellin from Sargassum muticum (Phaeophyceae) and Gracilaria corticata (Rhodophyta) harvested from Persian Gulf

Phytohormones are present in seaweeds but little is known about occurrence and content of them in seaweeds of Persian Gulf. The aim of this study was extraction of abscisic acid and gibberellin in Sargassum muticum and Gracilaria corticata. The seaweeds were collected bimonthly over one year at Bushehr coasts, Persian Gulf, during a range of environmental conditions. We explored new HPLC method for extracting abscisic acid and gibberellin from the seaweeds. It was found that the lowest amount of abscisic acid in Sargassum and Gracilaria were 0% in several months and the highest were 20.667 and 66.20% in November, respectively. Maximum yield of gibberellin in Sargassum and Gracilaria occurred in July (58.561%) and May (84.467%), respectively. The highest Sargassum biomass obtained in January (679 g/m2) and maximum biomass of Gracilaria was in March (423.33 g/m2). The results showed that biomass of two algae had negative correlation with abscisic acid and positive with salinity. This is due to inhibitory effect of abscisic acid on growth. There was no significant correlation between gibberellin and biomass of the two algae. In this article we showed that phytohormones existing in seaweeds of Persian Gulf could be used in algae liquid fertilizer.