A Salt-Tolerant Strain of Trichoderma longibrachiatum HL167 Is Effective in Alleviating Salt Stress, Promoting Plant Growth, and Managing Fusarium Wilt Disease in Cowpea

Salt stress is a constraint factor in agricultural production and restricts crops yield and quality. In this study, a salt-tolerant strain of HL167 was obtained from 64 isolates showing significant salt tolerance and antagonistic activity to . HL167 inhibited at a rate of 68.08% in 200 mM NaCl, penetrated under 200 mM NaCl, and eventually induced hyphae breaking, according to electron microscope observations. In the pot experiment, pretreatment of cowpea seedlings with HL167 reduced the accumulation level of ROS in tissues and the damage caused by salt stress. Furthermore, in the field experiment, it was discovered that treating cowpea with HL167 before root inoculation with can successfully prevent and control the development of cowpea Fusarium wilt, with the best control effect reaching 61.54%. Moreover, the application of HL 167 also improved the K /Na ratio of cowpea, alleviated the ion toxicity of salt stress on cowpea, and HL167 was found to effectively colonize the cowpea roots. HL167, which normally survives in saline-alkali environments and has the functions of disease prevention and plant growth promotion capabilities, has important research implications for improving the saline-alkali soil environment and for the sustainable development of green agriculture.