Innovative strategies for salinity stress management in Mango nursery plants: Agrobacterium fabrum and Glycine betaine approach

Abstract

This study investigated the impact of Agrobacterium fabrum (A. fabrum) and glycine betaine (GB) on mango seedling performance under saline and non-saline conditions using a randomized complete block design with three replications. Salinity stress was imposed based on electrical conductivity (EC), with two levels: 2.77 dS m^{- 1} (non-saline) and 6.56 dS m^{- 1} (saline). Application of A. fabrum in combination with 0.4% GB significantly improved seedling growth and physiology under salt stress. Agronomic traits, including scion and rootstock height, diameter, and biomass (fresh and dry weights), were markedly enhanced, with increases ranged from 18.34 to 79.47%. Physiological parameters such as chlorophyll content, relative water content, photosynthetic rate, stomatal conductance, and transpiration rate were also improved by about 20.04-88.06%. Mechanistically, these improvements suggest that A. fabrum likely enhanced nutrient uptake and root vigor, while GB functioned as an osmoprotectant, stabilizing cellular structures and maintaining water balance. Their synergistic action effectively mitigated salt-induced oxidative and osmotic stress, thereby promoting overall mango seedling resilience.