Morphophysiological alterations in young plants of Curatella americana L. subjected to shading

Abstract

Curatella americana, is the only representative of the genus Curatella found in Brazil. The species is regarded to have a high ecological importance value in the Brazilian Cerrado formations. Since plant species from this biome are under constant threat due to its degradation, studies aiming to elucidate the behavior of these species are important for future projects of land recovery. This study aimed to evaluate growth, development and gas exchange in C. americana saplings subjected to different shading levels. Ten samplings were subjected to two treatments: full sun and 76% shade, at 90 days after germination. At regular 60-day intervals, measurements of stem base height and diameter, and number of leaves, were taken. After 240 days from the beginning of the experiment, measurements of gas exchange (net photosynthesis, stomatal conductance, Ci/Ca ratio, and transpiration rate) were taken, and the content of photosynthetic pigments and stomatal density were determined. Plants under full sun showed higher development than plants under shading, presenting significantly higher values of number of leaves, stem base diameter, photosynthetic rate, stomatal conductance, transpiration rate, and Dickson Quality Index. Our results indicate that the species can be introduced along with pioneer species in land revegetation programs.