Effects of Fertilization, Arbuscular Mycorrhiza, and Salinity on Growth, Yield, and Bioactive Compounds of Two Aloe Species

Three greenhouse experiments were carried out to compare the responses of Aloe\r\narborescens and Aloe barbadensis with organic fertilization (standard or reduced fertilization\r\nlevel), arbuscular mycorrhiza [with AM(+AM) or without AM (–AM)], and salinity (1\r\nor 80mM NaCl) in terms of plant growth, leaf yield, mineral composition, and nutraceutical\r\nvalue. In all experiments, the yield of fresh leaves was significantly higher by 320%, 252%,\r\nand 72%, respectively, in A. barbadensis in comparison with A. arborescens. Doubling the\r\nfertilizer dose, plant growth parameters increased, but the bioactive compounds were\r\nnegatively affected. The highest antioxidant activity was recorded with A. barbadensis using\r\nboth fertilization regimes, whereas the highest values of anthraquinones aloin were observed\r\nin A. barbadensis using a reduced fertilization regime and when plants were\r\ninoculated with AM fungi. b-polysaccharide concentration was significantly higher in A.\r\nbarbadensis in comparison with A. arborescens and was increased by 33%when plants were\r\ninoculated with AM fungi. In both Aloe species, increasing the salinity decreased the leaf\r\nfreshweight and total dry biomass but increased the aloin and b-polysaccharides content by\r\n66% and 21%, respectively. The results suggest that cultural practices such as organic\r\nfertilization, inoculation with AM fungi, and irrigation with saline water can represent\r\neffective tools to achieve a more favorable phytochemical profile.