Growth and nodulation of alfalfa-rhizobia symbiosis under salinity: electrolyte leakage, stomatal conductance, and chlorophyll fluorescence

Authors : Lahbib Latrach, Mohamed Farissi, Mohammed Mouradi, Bouchra Makoudi

Pages : 320-326

Doi:10.3906/tar-1305-52

View : 15 | Download : 6

Publication Date : 9999-12-31

Article Type : Makaleler

Abstract :The present work was a study on the adverse effects of salinity on growth, nodulation, and some physiological parameters in 4 symbiotic combinations involving 2 Moroccan alfalfa (Medicago sativa L.) populations (Demnate and Tata) and 2 rhizobial strains (rhLAr 1 and rhLAr 4). The experiment was conducted in the greenhouse at 32/22 °C day/night, 50%-80% relative humidity, and a photoperiod of 16 h. The seedlings were separately inoculated with suspensions of 2 rhizobial strains and grown under 2 NaCl treatments, 0 mM (control) and 100 mM (salt stress), in plastic pots filled with sterile sand and peat at 9/10 and 1/10 ratios, respectively. The salt stress was applied for 5 weeks and some agro-physiological and biochemical parameters related to salt tolerance were assessed. The results showed that salinity significantly reduced the height of plants, their dry biomass, and nodulation. This constraint has also negatively affected the relative water content of leaves, the membrane permeability, the stomatal conductance, the maximum quantum yield of photosystem II, and the chlorophyll contents. Comparison among the symbiotic combinations tested showed that their behavior was significantly different. Plants inoculated with rhizobial strain rhLAr 4 were more tolerant to saline conditions. Their tolerance was associated with the maintaining of adequate levels in terms of physiological and biochemical parameters studied.
Keywords : Key words: Alfalfa, growth, nodulation, salinity, tolerance