Micropropagation and genetic uniformity of Kalanchoe daigremontiana (Crassulaceae)

Abstract

Kalanchoe daigremontiana is an ornamental species propagated exclusively asexually. However, no in vitro studies have been conducted to assess the relationship between changes in the culture environment and genetic variations of K. daigremontiana. Therefore, this study aimed to determine the optimal concentration of salts in the Murashige & Skoog (MS) medium and the optimal concentration of sucrose in the culture medium, in addition to the quality of light, in the development of in vitro plantlets from leaf explants of K. daigremontiana. Additionally, a genetic evaluation of the resulting plantlets was conducted to study phenotypic changes that could be attributed to somaclonal variation using Random Amplified Polymorphic DNA (RAPD) markers. For this purpose, leaf explants of K. daigremontiana were disinfected and inoculated in different salt concentrations (25, 50, and 100%) of MS medium without sucrose. The cultures were transferred to a growth chamber and subjected to three light conditions (white, blue, and red) with a 16-hour photoperiod, plus the absence of light, at a temperature of 27 ± 1 °C. Explants were also inoculated in 50% salt concentrations of MS medium supplemented with various concentrations of sucrose (control - without sucrose, 1.5, 3.0, 4.5, and 6.0%). K. daigremontiana leaf explants showed optimal development under white light and in any MS medium salt concentrations. A sucrose-free culture medium was viable, and no genetic variation was observed in the plantlets compared to the parent plants under the tested conditions.