Endogenous Phytohormones of Fern Polystichum aculeatum (L.) Roth Gametophytes at Different Stages of Morphogenesis in vitro Culture

The content of indole-3-acetic (IAA), gibberellic (GA 3 ), abscisic acids (ABA), and cytokinins—zeatin (Z), zeatin glucoside (ZG), zeatin riboside (ZP), isopentenyladenin (iР), and isopentenyladenosine (iРА)—was determined using the method of high-performance liquid chromatography in fern Polystichum aculeatum gametophytes at different stages of morphogenesis in vitro culture. It was shown that, at the stage of spatulate prothallium development, gametophytes contained significant amounts of GA 3 and IAA, while the content of ABA and cytokinins was low. The inactive ZG and active iP were dominant. At the stage of cordiform thallus formation, the level of GA 3 increased by 1.6, IAA by 2.4, and ABA by 1.7 times. The content of inactive iPA increased twice, significantly increased the level of active ZR and iP. At the development stage of sporophyte on the surface of gametophyte thallus, the levels of IAA, ABA, and GA 3 decreased. The accumulation of inactive ZG and decrease in the content of active zeatin and zeatin riboside were documented. At all stages of gametophytes’ morphogenesis, GA 3 was dominant, and its highest content was detected during the development of archegonia and antheridia. The pattern of gibberellic acid and zeatin riboside accumulation has shown the key role of these hormones in the regulation of growth processes and the development of reproductive structures of P. aculeatum gametophytes.