Salinity indicators in pineapple grown in the absence and presence of growth regulators/Indicadores de estresse salino em abacaxizeiro cultivado na ausencia e presenca de fitorreguladores

To assess the effects of salt on the pineapple MD Gold during the multiplication and rooting phases in vitro, this study evaluated its performance in different concentrations of NaCl in the absence or presence of growth regulators. Pineapple shoots were inoculated on MS solution in the absence and presence of the growth regulators naphthaleneacetic acid (NAA) and 6-benzlaminopurine (BAP) and different concentrations of NaCl (Control--0, 50, 100 and 150 mM). Monthly, shoots were subcultured and it was analyzed height, number of alive and dead leaves, and the rates of sprouting and rooting. During the multiplication in the absence of NAA and BAP, the NaCl treatments caused significant reduction in growth and development of pineapple shootings, expressed by the height and number of leaves, in the highest dose, which was not observed in the presence of growth regulators. During the first 60 days, an increase in leaf production occurred. However, after 90 days, there was a decrease in average living leaves in the shoots treated with salt. The in vitro cultivation of pineapple in the presence of salt is more efficient in the presence of NAA and BAP, ensuring continued growth, increasing the number of leaves, producing new buds and accelerating the process of rooting.