Trocas gasosas, crescimento e comportamento bioquímico em plantas jovens de Paricá (Schizolobium Amazonicum Huber ex Ducke) em diferentes concentrações de cádmio

Abstract

The aim of this work was to evaluate the physiological, growing and biochemical parameters of young plants of (Schizolobium amazonicum Huber ex Ducke) when submitted in diferente dosages of cadmium. The experimente was developed in greenhouse of Instituto de Ciências Agrárias (ICA), belonging to Universidade Federal Rural da Amazônia (UFRA), located in Belém-Pará, in a period of december 2017 to june 2018. Initially seedlings were produced from paricá seeds from Associação das Indústrias Exportadoras de Madeira do Estado do Pará in Benevides-Pará. The seeds were seeded in a Leonard type pot with a capacity of 4.6 L adapted with pet bottles containing washed and sterilized sand. After 15 days after sowing, they received nutritive solution of Sarruge (1/4 and 1/2 strength). After 60 days after sowing the application of increasing concentrations of cadmium in the form of cadmium chloride (CdCl2.H2O). Was utiized a randomized experimental design (RED), with 5 treatments being constituted of control plants (without cadmium dosages) and with cádmium dosages(CdCl2 178μM, CdCl2 356 μM, CdCl2 534μM, CdCl2 712 μM) with 7 repetitions each (one plant per pot) totalizing 35 experimental units. The obtained data were submitted to variance analysis by F test (p < 0,05) and the means were compared by the least significant difference of the Tukey's test (p<0,05) and were adjusted by polynomial regression equations P <0.01 or 0.05 using the Sisvar program. The mainly physiological variables (photosynthesis, stomatal conductance and transpiration) destabilized in their functions with the increase of the cadmium doses, influencing in the energy process of the same ones. The growth, diameter, leaf number and leaflet variables, cadmium provided a reduction as the doses were increased, interfering in the production of foliar biomass. Changes in physiological effects have consequently led to changes in plant metabolism and nitrogen, evidencing the low concentrations of nitrogen-containing molecules in their structures such as amino acids, proline, and glycine. The cadmium accumulated in the roots, but there was a translation for the aerial part. Given this, it can be corresponded as a phytoextractor.