Silício melhora a qualidade de mudas de batata-doce in vitro

Abstract

Sweet potato is one of the most consumed vegetables in Brazil. For being a culture considered rustic, its form of cultivation was, for a long time, neglected. This condition caused this species to have low productivity, especially when the same vegetative materials were successively used for plant multiplication. With the intention of increasing its productive efficiency, in vitro micropropagation began to be used as a technique for the multiplication of individuals of this species, which contributed to the production of seedlings with high phytosanitary and genetic quality. In addition, it also enabled the development of research to determine, in vitro, the best concentrations of mineral elements, such as silicon (Si). Si is a mineral element considered beneficial for several cultures, and there are also reports that its in vitro use favors important morphological aspects in different species. Based on the above, the objective of this work was to evaluate the development of sweet potato seedlings micropropagated and subjected to different concentrations of Si in the form of diatomaceous earth. For that, explants established in vitro were used, being inoculated in MS culture medium added with four concentrations of diatomaceous earth (0.5; 1.0; 1.5; 2.0 g L-1) plus the control (without diatomaceous earth). The experiment was carried out in a completely randomized design, with 15 replicates and two explants per flask. After 30 days in a growth room, the following phytotechnical characteristics were evaluated: number of leaves, shoot height (cm), stem diameter (cm), number of senescent leaves, shoot and root fresh mass (mg), and dry mass of shoot and root (mg). The seedlings did not show statistical difference between them regarding the number of leaves, shoot height and stem diameter. For the number of senescent leaves, the treatment with 2.0 g L-1 of diatomaceous earth showed the best result. For fresh and dry mass of the aerial part and fresh of the root, they presented greater mass with the increase of the concentrations of diatomaceous earth in the culture medium. It can be concluded that the addition of silicon in vitro, in the concentration of 2.0 g L-1 of diatomaceous earth, provides the obtaining of sweet potato var. Campina plantas with higher phytotechnical quality, higher mass and lower senescence effects.