Toxicidad del cobre sobre la morfología de estomas de Gochnatia arequipensis Sandwith (Asteraceae) de dos localidades de Arequipa, Perú

Abstract

The excess of heavy metals, such as copper, causes toxicity in plants, consequently, it generates changes in their aerial tissues, affecting their stomata whose main function is gas exchange. However, the density and morphometry of these stomata could vary to compensate for the water content caused by these environmental changes. The purpose of this study was to determine the leaf area, density and morphometry of leaf stomas of Gochnatia arequipensis Sandwith (Asteraceae) in relation to leaf copper content, determined by atomic absorption spectrophotometry, collected at different sampling points. In this research, a stratified design was carried out, for which leaves of the study plant developed in the district of Quequeña were collected at different distances from the tailings belonging to the Kiowa PAM and also in the Characato district. The leaf area was lower in plants from the points closest to the Kiowa PAM (55.8 ± 11.27 mm2) than the leaf area of the Characato district plants (62.72 ± 6.94 mm2). On the other hand, the stomatal density (154.2 ± 32.9 stomata / mm2) was greater in the plants of the points near the Kiowa PAM while its stomatal area decreased (315.02 ± 31.114 μm2). The stomatal opening was greater in the Characato plants (73.04 ± 8.3 μm2). When the amount of leaf copper is greater, the leaf area suffers a decrease, the stomatal density decreases as the plants move away from the Kiowa PAM.