en Ecology Ecology پژوهشي Orginal research papers <span style="font-size:14pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="font-size:12.0pt"><span style="line-height:120%"><span style="color:black">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 <i>Sargassum muticum</i> and <i>Gracilaria corticata</i>. 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 <i>Sargassum</i> and <i>Gracilaria</i> were 0% in several months and the highest were 20.667 and 66.20% in November, respectively. M</span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span style="color:black">aximum yield of gibberellin in <i>Sargassum</i> and <i>Gracilaria </i>occurred in July (</span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span style="color:black">58.561</span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span style="color:black">%) and May (84.467%), respectively. The highest <i>Sargassum</i> biomass obtained in January (679 g/m²) and maximum biomass of <i>Gracilaria</i> 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. <a name="_Hlk63179949">This is due to inhibitory effect of abscisic acid on growth</a>. 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.</span></span></span></span></span></span> Abscisic acid, Gibberellic acid, Algae, Persian Gulf 590 604 http://jifro.ir/browse.php?a_code=A-10-3707-2&slc_lang=en&sid=1 H. Saebmehr h.saebmehr@gmail.com 100319475328460045581 100319475328460045581 No Department of Natural Resources and Environment, Science and Research Branch, Marine Biology Group, Islamic Azad university, Tehran, Iran. F. Rafiee farnaz.rafiee47@gmail.com; 100319475328460045582 100319475328460045582 Yes Department of Marine Biology, Islamic Azad university, Tehran, Iran G. Mostafavi golaleh.m@gmail.com 100319475328460045583 100319475328460045583 No Department of Biology , Islamic Azad university, Tehran, Iran M.H. Givianrad givianradh@yahoo.com 100319475328460045584 100319475328460045584 No Department of Chemistry, Islamic Azad university, Tehran, Iran