Abstract
Background and Aims Highly specialized halophilic flora, such as the threatened endemic sea-lavender species Limonium algarvense and Limonium daveaui, are adapted to grow in saline environments. Plant-associated microorganisms associate with halophytes promoting their survival and growth, namely stress tolerance. In this study, we compared the effects of halophilic bacterial inoculants and characterized seed germination and plant growth under saline conditions.Methods A new protocol was developed for in vitro seed germination with bacterial inoculation. The experimental set up included three treatments: non-inoculation, inoculation with a single bacterial inoculum (Pantoea sp., LDR15) or a consortium of halotolerant bacteria (Pantoea genus). We assessed plants’ physiological status, biomass, and leaves characteristics under saline irrigation.Results Exposure to NaCl (200 mM) along with inoculation using either LDR15 strain or the bacterial consortium negatively affected seed germination. The inoculated bacteria were localized in root cortex and phloem. Under non-saline conditions, bacterial inoculation had no effect in leaf number and fresh biomass, being leaf reflectance values higher in L. algarvense than in L. daveaui. Salinity significantly reduced both leaf number and size, succulence and biomass, being this effect more pronounced in L. algarvense than in L. daveaui. The bacterial consortium negatively affected plant survival, but plants inoculated with the LDR15 strain had higher biomass than the non-inoculated ones.Conclusion We concluded that even though halotolerant bacteria did not improve seed germination upon salinity exposure, the bacterial inoculation with LDR15 strain in germinated plantlets can be a suitable strategy for promoting plant development in saline environments.