PSEUDOMONAS-MEDIATED ALLEVIATION OF SALT STRESS IN VICIA FABA: RHIZOBACTERIAL ENHANCEMENT OF GERMINATION AND IMPLICATIONS FOR SUSTAINABLE AGROECOSYSTEMS

Soil salinity poses significant environmental challenges to plant life, affecting all organs and developmental stages.Osmotic stress is the primary mechanism by which salinity impairs seed starch hydrolysis and embryo emergence during germination.Plant growth-promoting rhizobacteria (PGPR) inoculation, especially Pseudomonas species, has gained interest for mitigating abiotic stress effects.This study investigated the effect of rhizospheric Pseudomonas on the germination of two Vicia faba varieties (Aguadulce and a local Algerian variety) under saline conditions.Seeds were surface-sterilized and imbibed in distilled water (control) or NaCl solutions (100 or 200 mM), with or without bacterial inoculation (three selected strains).Germination percentage, speed, and mean germination time (T₅₀) were recorded over nine days at 25 °C.Salinity reduced germination percentage and delayed germination in both varieties.In non-saline conditions, bacterial inoculation enhanced germination percentage but also increased T₅₀.Under salt stress, Pseudomonas strains significantly improved germination percentage and speed in the Aguadulce variety, but not in the local variety.Among strains, SHA21 was most effective for Aguadulce seeds under salinity.These results suggest that PGPR inoculation can enhance the salt tolerance of V. faba seeds, with varietal differences in responsiveness.Beyond immediate agronomic outcomes, these findings carry broader implications for sustainable legume cultivation: Vicia faba's capacity for biological nitrogen fixation, its role in fostering soil microbiome diversity, and its value as a pollinator resource position it as a keystone species for agroecosystem biodiversity and sustainable development.