Physiological responses of the two blueberry cultivars to inoculation with an arbuscular mycorrhizal fungus under low-temperature stress

Effects of the arbuscular mycorrhizal fungus (AMF), Glomus mosseae, on growth, antioxidant, osmoregulation, and nutrition were investigated in Britewell (Vaccinium ashei) and Misty (Vaccinium corymbosum) plants exposed to low temperature (10 degrees C). At low temperature, the two cultivars showed similar decreases in leaf concentrations of soluble sugars, phosphorus (P), and potassium (K). However, similar increases were observed in levels of leaf antioxidants, malondialdehyde (MDA), hydrogen peroxide (H2O2), superoxide anion radical (), and proline. AM inoculation increased leaf activities of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, ascorbate, and glutathione, but decreased leaf concentrations of , MDA, and H2O2 in the two cultivars. AMF caused greater changes in leaf composition in Britewell. AM-inoculated Britewell and Misty plants had higher concentrations of soluble sugar, proline, P, and K than non-AM-inoculated plants, especially in the former cultivar. These results indicate that G. mosseae has the potential to enhance resistance of Britewell blueberry plants against low-temperature stress.