Development of a method for propagating stevia based on in vitro

Abstract

Abstract. The purpose of the study is to develop a technology for the production of stevia planting material based on the method of clonal micropropagation and the use of silicon oxide at the stage of adaptation, evaluation of the effectiveness of the influence of silicon oxide in the adaptation of microplants. Methods. Commonly used in the practice of clonal micropropagation of plants were applied. Methods generally accepted in the practice of clonal micropropagation of plants were applied: sterilization of the initial material, introduction into culture in vitro, clonal micropropagation proper, rooting with subsequent adaptation to environmental conditions. The object of the study was stevia: at the stage of introduction into a sterile culture - seeds, at subsequent stages - microcuttings and microplants. At the adaptation stage, silicon oxide was used in the form of a solution of orthophosphoric acid at a concentration of 0.01%. Scientific novelty. The possibility of obtaining microplants at the stage of micropropagation itself, bypassing the stage of rooting, is shown. On the MS medium with epin 0.1 mg/l in combination with indolyl-3-acetic acid (IAA) 0.5 mg/l, high-quality plants of small sizes develop: shoot length on average 5.6 cm, well-formed unfolded leaves and root system, relatively short internodes. Research results. At the stage of introduction into a sterile culture during sterilization with a 33 % hydrogen peroxide solution in an exposure of 8–10 minutes, a high infection of seeds (about 70 %) and their low germination (10 %) were noted, which can be explained by the structure of the seeds and the biology of the species. At the stage of micropropagation itself, the maximum effect was obtained when MS 6-BAP was included in the nutrient medium at a dose of 0.5 mg/l. The combined inclusion of epin growth stimulants with IAA and IMA in the composition of the media contributed to the development of roots by 2.1 points and 1.8 points, respectively, which was at the control level – 1.8 points. On media with cytokinins, the roots were weakly expressed (0.3 points with 6-BAP) or absent (with kinetin), which was a significantly worse result compared to the control. The output of adapted microdenies in the spring amounted to 80 %. However, during the summer landing for adaptation, a decrease in the survival rate of plants was observed. In order to increase the efficiency of adaptation, we used 0.01 % silicon oxide.