Moringa leaf extracts as biostimulants-inducing salinity tolerance in the sweet basil plant

Abstract

HORTICULTURE plants are constantly exposed to salinity problems during growing. Biostimulants from plants origin known to protect plants growth and improve their productivity within a varied conditions of salt stress. To investigate Moringa plants (Moringa oleifera, MO and Moringa peregrena, MP) activity as biostimulants, sweet basil (Ocimum basilicum L. cv. cispum) plants grown with/or without salt stress were irrigated using aqueous leaf extracts from both species. Two hundred grams of fresh Moringa leaves were homogenized in one liter distilled water, filtered and the dilutions: 2.5%, 5.0%, 10% and 20% were made. In stressed basil, proline and malondialdehyde had increased then decreased significantly with both Moringa extracts, particularly with MP treatment. Compared to control basil, 10% was the best concentration that caused enlargements of basil leaf area by 60% during salt stress. On applying 10% MO and MP extracts to salt-stressed basil, growth parameters like shoot length were increased by 32% and 38%, shoot fresh weight by 50% and 109%, shoot dry weight by 123% and 84%, number of branches by 75% and 87%, root length by 40% and 63% and root dry weight by 142% and 225%, respectively. MO treatment led to a significant increase in anthocyanin, total carbohydrates and superoxide dismutase in basil. Alternatively, MP increased ascorbic acid oxidase actively in basil leaf. The varied chemical composition of Moringa species underlined the resistance strategies in basil. We hypothesized that the efficacy might even become much more potent on basil with the simultaneous irrigation using the two species of Moringa.