Use of microalga Asterarcys quadricellularis in common bean

Common Bean ( Phaseolus vulgaris ) is considered one of the most affordable sources to tackle hunger in underdeveloped countries. However, its cultivation takes place in regions that suffer from water deficiency, which limits plant growth and crop yield. Therefore, it is necessary to seek sustainable alternatives that mitigate the deleterious effects of water shortage. The aim of this study was to evaluate the potential for mitigating the effects of water deficit with the application of the chlorophyte microalga Asterarcys quadricellularis (CCAP 294/1) in two bean cultivars (IAC 1850 and BRS ESTEIO). The plants were grown in pots, with foliar application of microalgae at stage of third fully expanded trefoil at concentrations of 0.5 mL L −1 and 1.0 mL L −1 . The water deficit lasted for 7 days and, after that, the rehydration of the plants was performed. Evaluations were carried out in three periods: i. on the third day after the start of water restriction, ii. one day after rehydration, iii. 10 days after rehydration. The levels of chlorophyll, sugars, protein and antioxidant enzymes were increased in plants treated with microalgae. At ten days after rehydration, there was an increase in leaf area, fresh mass, and leaf thickness in the treated plants, characterizing the biostimulant effect of microalgae. Our results demonstrate the effects of A. quadricellularis in mitigating the deleterious effects of water deficit, accelerating the recovery of the two common bean cultivars, which demonstrates its potential as a sustainable alternative to support food production under changing environment.