Otimização de protocolo de multiplicação in vitro de cana-de-açúcar (Saccharum spp.) geneticamente modificada

Abstract

Sugarcane is one of the main agricultural crops in Brazil. Responsible for the largest source of sugar in the world, it is also an important alternative source of fossil fuels, through ethanol. The improvement through genetic engineering techniques brings a significant impact in the fields of agriculture and industrial production, mainly in the control of pests, diseases and physiological changes. However, after generating genetically modified plants, few in vitro propagation protocols are adapted to explant sources from genetic transformation. In addition, in vitro multiplication processes may carry a risk of phenotypic/somaclonal variation due to the long exposure of plants in tissue culture. Thus, in this work, four main stages of the process were investigated: beginning of vegetative propagation, explant establishment, temporary immersion bioreactor phase and rooting. Through the parameters tested in the experiments, a protocol for the in vitro multiplication of sugarcane was optimized, using a 50 mL Falcon tube as a container for the propagated material in the stages of initiation and establishment of the explant. Afterwards, management techniques such as pruning and cleaning and optimized immersion schedules, culture medium permanence and change interval in the bioreactor phase, and establishment in the rooting stage of the culture medium composed of 20 g/L of sucrose and ANA growth regulator, in addition to seedling dismemberment for nutrient absorption. With the optimization of the established protocol, there was a reduction in the process time from 20 to 15 weeks, equivalent to a 25% gain in relation to the in vitro culture time of the original protocol.