Propagação vegetativa por alporquia e otimização de protocolo de estabelecimento in vitro de mangabeira (Hancornia speciosa Gomes)

• Autor(a) principal: Tiago, Bruno dos Santos
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/13035
• topic: Cerrado; Mangaba; Propagação; Cultura de tecidos; Propagation; Tissue culture; CIENCIAS BIOLOGICAS::GENETICA::GENETICA VEGETAL

Hancornia speciosa Gomes, popularly known as mangabeira, is a native fruit species of the Cerrado used for food purposes and as herbal medicine. Currently, due to habitat loss and predatory extraction, there is a great demand in more studies for the conservation and use of this fruit species. The main challenge for the in vitro establishment of the species is the high number of endophytic agents (fungi and bacteria) that are present in plant tissues. This makes it more difficult to introduce plant material into the in vitro culture. This work aimed to optimize the in vitro establishment protocols in addition to carrying out vegetative propagation, via layering, generating clones of matrix plants. For the in vitro establishment of one of the varieties of the species, var. gardineri, first the fall fruits were collected in the Collection of Native Fruits of the Cerrado of the School of Agronomy at UFG. Fruits were pulped and 80 seeds were selected, which had their tegument removed and proceeded to the decontamination process. In a laminar flow chamber, two groups of seeds were separated: 40 seeds were opened and their embryos exposed, isolated and inoculated in MS culture medium; the other 40 seeds were inoculated directly in MS culture medium. To test the effect of stretching on reducing the period of development in vitro, embryos were inoculated in treatments with 0, 1, 2 and 4 μM of gibberellic acid (GA3) and later in a second experiment in MS medium with 1,0 μM of 6-benzylaminopurine (BAP), with lower concentrations of GA3: 0.2; 0.4; 0.6; 0.8 and 1 μM. For the next stage, treatments were carried out to root the new shoots with indolbutyric acid (IBA) in concentrations 0, 1, 3, 5 and 7 mg.mL-1 . The germination of the isolated embryos showed less than 5% of contamination and was 30% faster when compared to the seed. The effect of GA3 on isolated embryos allowed the plant to elongate with 0.8 μM, reaching 130 mm in 75 days, reducing in vitro cultivation by more than 100 days. In rooting, the concentration of 1 mg.mL-1 of AIB allowed more than 9 roots per plant and an average length of 54 mm. The acclimatization of the treatment plants took place on substrate with 50% sand and 50% broad red soil with commercial substrate. In this process, mortality was less than 10%. The layering experiments were carried out with four varieties of H. speciosa: gardineri, speciosa, cuyabensis and pubescens and in two different seasons: the dry season, and the rainy season. AIB was used to induce rooting at concentrations of 0, 4, 5 and 6 mg.mL-1 , with 15 ml per branch. The substrate used was soil humidified with commercial substrate fixed to the ringed branch. After 180 days, the best results were in the concentration of 5 mg.mL-1 in the four varieties used. However, the results for each variety were at different times of the year, due to the specific phenological phases.