Resumo

FRANCO-SALAZAR, Víctor A  e  VELIZ, José A. Responses of the cactus-pear [opuntia ficus-indica (l.) Mill.] to nacl. INCI [online]. 2007, vol.32, n.2, pp.125-130. ISSN 0378-1844.

In order to study the effect of NaCl on the physiology of Opuntia ficus-indica, the plant was cultured hydroponically at concentrations of NaCl of 0, 50, 100 and 150mol·m^-3. Growth (volume and relative growth rate), relative water content (RWC), protein, proline and ion (Na⁺, K⁺ and Cl^-) contents were determined in basal and apical cladodes and roots. Even though the plant survived all treatments, the increase in salinity affected its growth and RWC, especially at 150mol·m^-3 of NaCl. Protein content did not change in the chlorenchyma of basal cladodes, but decreased in roots, and increased in the hydrochlorenchyma of basal cladodes and chlorenchyma of apical cladodes. Proline content increased in both cladode types and roots, particularly, at the highest NaCl concentration. Accumulation of Na⁺ and K⁺ in basal cladodes, accumulation of Na⁺ and a decrease in K⁺ content in roots, and accumulation of Cl^- in both cladode types and in roots occurred as salinity increased. The higher proteins, proline and K⁺ content alleviated the negative effects generated by salinity, allowing an adequate water economy and protecting photosynthetic tissues.

Palavras-chave : Cladodios; NaCl; Opuntia ficus-indica; Prolina; Salinidad.