Micropropagation of Achyrocline flaccida (Weinm.) DC. in liquid culture media

Abstract

Achyrocline flaccida, known by the popular name of ‘Marcela’, is a plant native from Uruguay, south of Brazil, Argentina and Paraguay, frequently found in sandy and stony ground. Its productive interest lies in Marcela´s content of high levels of quercetin, a flavonoid with important antioxidant and cytoprotective properties. In order to increase the propagation scale of the species, the multiplication in liquid medium employing bioreactors was evaluated. Bioreactors represent an efficient plant micropropagation system, avoiding intensive manipulation and reducing costs. Hyperhydricity represents the main limitation of the system. Submerged tissues suffer stress, and the plants obtained show different anatomical and physiological anomalies that may affect their survival ex vitro. Our objective was to optimize a system for the production of A. flaccida microplants in bioreactors, which could allow the scaling up of production. The effect of phloroglucinol to prevent hyperhydricity promoting lignin biosynthesis was assessed, and confirmed with light microscopy. For all treatments multiplication rate was higher than that employing solid medium, with a maximum of 11 micro cuttings per bud in two months. Rooting and survival ex vitro was close to 100 %. These results represent an effective reduction of costs as less manual labor and media components are required. An efficient system has been developed which will contribute to increase the stock of good quality plant material available.