Development of Biofertilizer from Local Qatari Cyanobacteria Strains for Enhancement of Bell Pepper (Capsicum annuum L.) Growth, Yield, and Abiotic Stress Tolerance under Hydroponic System

Abstract

The beneficial cyanobacteria strain (blue-green algae) Roholtiella sp. QUCCCM97 has been found to be the origin of an eco-friendly and environmentally safe biofertilizer whose extract and biomass were used to increase the productivity of bell pepper (Capsicum annunm L.) in hydroponics. From the collection of hundreds of Qatari cyanobacteria strains, three strains QUCCCM97, 99, and 112 were characterized and classified according to morphological and molecular identification. Then, a preliminary investigation showed that the three strains were effective growth promoters to bell pepper seedlings with QUCCCM97 being the most efficient. Consequently, a scale-up experiment (large scale/mini commercial scale) was conducted to further study the effect of its extract and water re-suspended biomass as biofertilizers through foliar application under a hydroponic system. Besides, the extract was also investigated to treat salinity stress on bell pepper seedlings at different concentrations via a foliar application under a soilless technique. Summarily, QUCCCM97 was found to significantly increase the vegetative parameters, biochemical/nutritional constituent, and crop yield with respect to conventional fertilization alone. Also, QUCCCM97 significantly mitigated the effect of salinity at different concentrations (0, 50, 100, 150, and 200 mM) on vegetative growth parameters and biochemical constituents. Based on our findings, we assume tentatively that the QUCCCM97 strain could be a novel species as no prior identification is found in the GenBank.