Obtaining of the fertile sunflower-regenerants (Helianthus annuus L.) by in vitro organosesis

Abstract

Sunflower (Helianthus annuus L.) is one of the mainoilseeds in the world and by far one of the hardestcrops to cultivate in vitro. Currently, there is no registrated transgenic sunflower (Helianthus annuus L.) variety (clone, line, F1 hybrid, population). One ofthe main problems for obtaining transgenic plants isan efficient in vitro regeneration system, which willmake it possible to obtain morphologically typical fertile regenerants. It is known that the regenerative ability of sunflower can be studied in two ways: somatic embryogenesis and direct organogenesis. Due to the different ratio of growth regulators such as auxin and cytokinins, it is possible to influence the frequency of regeneration from different types of tissues. Thus, at high concentrations of auxins and low concentrations of cytokinins, it is possible to induce root regeneration. And for the induction of shoot regeneration, it is better to use high concentrations of cytokinin and lowconcentrations of auxins. However, knowing differentapproaches and methods of sunflower cultivation invitro regeneration culture, today there is no universalprotocol that is suitable for all sunflower genotypes.That is why the aim of our work was to investigatethe regenerative capacity of sunflower lines and develop an effective system that will later be used forgenetic research in order to improve economicallyvaluable traits of sunflower. This article presents data on sunflower regeneration (Helianthus annuus L.) by direct organogenesis.Cotyledons of immature seeds (21 days after pollination) were used as explants. The induction andproliferation of adventive buds was tested in a basicmedium with different concentrations of growth regulators. It was found that the optimal conditions for the induction and proliferation of adventive buds is a modified MS medium supplemented with vitamins for Gamborg, 5 mg/l AgNO3, 2 mg/l 2–isopentenyladenine (2–iP), 0.5 mg/l indole–3–acetic acid (IAA), 0.1 mg/L thidiazuron (TDZ).The elongation of adventitious shoots was carried out on a modified MS medium with Gamborg vitamins, 5 mg/L AgNO3, 1 mg/L 2-IP, 0.5 mg/L N6-benzylaminopurine (BAP). We were the development of an effective in vitro rooting system allowed to obtain seeds.