NUTRIENT MEDIUM GELLING AGENT EFFECT ON EMBRYO- AND CALLUSOGENESIS IN ISOLATED OVULES OF RED BEET (BETA VULGARIS L.)

Abstract

Gynogenesis is the only way to form haploid embryoids, which underlies the technology of creating doubled haploids of Beta vulgaris L. plants of the species, including red beet. The composition of nutrient media has a significant influence on embryo- and callusogenesis in the culture of isolated ovules and the final yield of regenerated plants. In early works, researchers studied the effect of growth regulators, organic components, the consistency of nutrient media. In standard protocols for the culture of sugar beet isolated ovules, agarose, agar, and phytagel are gelling agents for the nutrient medium. At the same time, there are no studies of the use of various gelling agents’ effectiveness compared to each other. During the cultivation of isolated red beet ovules,only agar was used to gelate the nutrient medium. At the same time, gelling agents and their concentration determine the mobilization of nutrient media; have various effects on explants, their vitrification, and the quality of regenerants. The selection of optimal gelling agent of the nutrient medium for cultivating isolated beet ovules can increase the yield of embryoids, callus, and regenerant plants and is relevant for research. In this work, we have studied the effect of gelling agents (agar, agargel, phytagel, and agarose) in the nutrient medium composition on embryo- and callusogenesis in the culture of isolated ovules of red beet (Beta vulgaris L.). Isolated ovules were cultured on MS nutrient medium supplemented with 200 mg/l BAP, 500 mg/l IAA, 60 g/l sucrose, and the following gelling agents: agar – 7.5 g/l; agarose – 6 g/l; agargel – 4 g/l; phytagel – 2 g/l. A Petri dish with 20 ovules represents repetition; the researchers experimented with 22 replicates. The researchers observed a higher yield of embryoids and callus when studying the effect of nutrient media gelling agents on the formation of embryoids and callus in the culture of isolated ovules in media containing phytagel and agarose. In contrast, in media containing agar and agargel, ovules formed callus and embryoids with a lower frequency, while agar has a more negative effect than agargel.