Physiological responses of arbuscular mycorrhizal fungus- Tamarix ramosissima Ledeb. seedling symbionts to drought stress

Arbuscular mycorrhizal fungi (AMF), as a class of soil microorganisms and green fertilizers, can form mutualistic symbionts with most vascular plants to promote growth under stress. Here, we explored the physiological responses of AMF-Tamarix ramosissima Ledeb. seedling symbionts to drought stress to study drought resistance of Tamarix ramosissima seedlings, a dominant species in the desert riparian forests in the lower reaches of the Tarim River. Two moisture gradients and two inoculation treatments were established. The moisture gradient included normal moisture (soil relative moisture content (70 ±5)%) and drought stress (soil relative moisture content (30 ±5)%) treatments. Inoculation included AMF inoculation treatment and no inoculation control. Results showed that:(1) Compared with the control, plant height, base diameter, and crown width increased in the Tamarix ramosissima seedlings inoculated with AMF by 24.6%, 9.1%, and 32.3%, respectively, under drought stress. (2) Compared with normal moisture treatment, the mycorrhizal infection rate of the Tamarix ramosissima seedlings decreased by 26.47% under drought stress. (3) Compared with the uninoculated plants, malondialdehyde (MDA) content decreased, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activity increased, and proline and soluble sugar content increased in the Tamarix ramosissima seedlings inoculated with AMF.