The effect of salt stress on the growth and development of three Aloe species in eastern Morocco

Abstract

The salinity stress is an abiotic factor that limits the growth of agricultural crops. Salinity affects over 800 million hectares of worldwide land. Aloe species are xerophytes, perennial plants with succulent leaves that have a crassulaceous acid metabolism also known as CAM photosynthesis, which allows these plants to conserve water during dry periods. These species have long been known for their cosmetic and medicinal properties. The effect of salinity stress on the growth and development of three Aloe plants (Aloe vera, Aloe brevifolia, and Aloe arborescens) was investigated in this study. Aloe plants were watered for four months at four different NaCl stress (0 mM, 51 mM, 103 mM, and 155 mM). Physiologically, no significant differences were recorded in chlorophyll content nor quantitative of salt stress whereas relative water content did. Morphologically, the NaCl concentration up to a level of 51 mM on the number and thickness of leaves was not significant. However, the overall biochemical parameters (proline, sugars, and polyphenols contents) were significantly increased due to the salinity stress. The salinity tolerance is highly seen in the conservation of good water state in these species. Furthermore, Aloe brevifolia is the most salinity tolerant species compared to the other two species studied, Aloe vera and Aloe arborescens.