Ação do enxofre em chuva ácida simulada sobre parâmetros morfofisiológicos de Phaseolus vulgaris L. (Fabaceae)

Abstract

The goal of this work was to evaluate the effects of sulfur and simulated acid rain on the leaf of Phaseolus vulgaris. Acid rain (pH 3.0) and an aqueous solution (Ph 6.0) were performed on test and control plants, respectively. A decrease in chlorophyll a, chlorophyll b and total chlorophyll concentrations was observed in the flowering stage (R6). However, increased rates were determined in the maturation stage (R7), which can suggest a resistance and/or adjustment of the plants to the acid simulation conditions. The acid treatment achieved chlorophyll degradation by oxidative processes without conversion to pheophytin. A reduction was also seen in the number of glandular and non-glandular trichomes and stomata on the test plants. Moreover, only small injuries were verified on the blade and peciolar areas of the tested individuals of P. vulgaris, probably due to the presence of the reported epidermal structures.