Genotipos de Portulaca oleracea L. ante estrés salino por NaCl: un análisis multivariado

Abstract

Purslane (Portulaca oleracea L.) is a species with potential under increasing salinity in agricultural soils and deep groundwater used for irrigation. Salinity is one of the most limiting abiotic factors for agricultural productivity in arid zones. This issue demands the identification of resilient crops with commercial value. For that reason, the aim of this investigation was to assess the morphological, pigmentary, bioactive compounds, and Cie L*a*b* responses of Mexican P. oleracea genotypes under salinity stress with a multivariate analysis. The experiment was conducted in Francisco I. Madero, Coahuila, Mexico. The Cuautla and Xochimilco cultivars and the Hoja Ancha variety were exposed to 0, 4, 8, 12, and 16 dS m-1. Growth variables, CIE color coordinates, bioactive compounds, and both photosynthetic and non-photosynthetic pigments were evaluated. The results indicated that salinity significantly reduced fresh biomass at 12 dS m-1, representing a decrease of up to 66% compared to the control. In contrast, photosynthetic (carotenoids, chlorophyll a and b) and non photosynthetic (betacyanins and betaxanthins) showed no statistical significance. Meanwhile, principal component analysis (PCA) revealed that the plant prioritizes the biosynthesis of phenolic compounds and antioxidant capacity over primary growth as a defense mechanism against salt stress. Furthermore, colorimetric variables showed an association with electrical conductivity. It is concluded that the studied P. oleracea genotypes possess salt stress tolerance up to 12 dS m-1, maintaining their nutraceutical quality even in the face of yield reductions.