Estabelecimento e otimização da micropropagação de Sinningia rupicola (Mart.) Wiehler : uma espécie ameaçada de extinção

Abstract

Ferruginous Rupestrian Grasslands constitute an ecosystem composed of diverse endemic and rare species, currently vulnerable due to anthropogenic activities and climate change. Among them, Sinningia rupicola (Mart.) Wiehler stands out, classified as "endangered". Micropropagation represents a strategic tool for the conservation of endangered species, as it allows for the large-scale production of high-quality seedlings. However, adjustments are necessary to meet the specific demands of each species. In this context, the general objective of this study was to establish an efficient micropropagation protocol for the species Sinningia rupicola. To this end, the research was structured in three chapters. The first chapter evaluated aseptic protocols for seed inoculation, gas exchange systems, and seedling acclimatization. The second chapter evaluated the effects of different spectral qualities throughout the cultivation stages. Finally, the third chapter sought to evaluate the effect of supplementation with zinc oxide nanoparticles (ZnO-NPs) in the culture medium for the in vitro cultivation of the species. Surface sterilization by immersion of the seeds in sodium hypochlorite for 5 minutes facilitated both germination and in vitro establishment. The membrane gas exchange system favored explant growth, and the use of a mini-greenhouse proved effective for acclimatization. Purple LEDs were considered the most suitable for cultivation, promoting balanced explant growth. Finally, the addition of ZnO nanoparticles to the culture medium, under the experimental conditions evaluated, inhibited rooting and induced explant senescence. Thus, the standard MS medium remains the most suitable for plantlets production. Based on these results, it was possible to produce Sinningia rupicola plantlets in adequate quantity and quality, contributing as a strategy for recovery and preservation programs for both the species and the biodiversity of the Rupestrian Grasslands.