Arbuscular Mycorrhizae Confers Salinity Tolerance to Medicago sativa L.

Alfalfa, a crop cultivated worldwide for use as livestock feed, exhibits great adaptability to various environmental conditions. This study evaluates the biomass production, lipid peroxidation, photosynthetic pigments and osmo-compatible response in Medicago sativa var CW660 mycorrhizae (AM) and non-mycorrhizae (NM) plants with Rhizophagus intraradices and when subjected to salinity (100 mM and 200 mM of NaCl). They were evaluated using the following morphological parameters: foliage fresh weight (FFW), foliage dry weight (FDW), root fresh weight (RFW), root dry weight (RDW), foliage length (FL) and root length (RL), chlorophylls a and b, proline and malondialdehyde (MDA) in AM and NM plants treated with different concentration of NaCl. The LFW and the LDW were higher in M plants. The RFW and the RDW increased in control AM plants, and under different saline treatments there were no differences between AM and NM in either parameter. FL increased in the control and at 100 mM of NaCl in M plants. Chlorophyll a decreased 27–30% and b decreased 1–50% in AM and NM plants at 200 mM NaCl. The proline level increased four times and promoted a defense in AM plants at 200 mM of NaCl. Lipid peroxidation decreased in AM plants by 10% at maximum salinity. M. sativa CW660 is sensitive to salinity stress, and inoculation with arbuscular mycorrhizal fungi (AMF) regulates its physiology and performance under such conditions, with osmotic protection and membrane protection.