Screening of plant growth-promoting bacteria in alfalfa grownin saline in Cangzhou, Hebei Province

This study focused on Medicago sativa growing in Huanghua City, Cangzhou, Hebei Province. Soils adhered to M. sativa roots were sampled from10 different locations in Huanghua City, including Zhaozizha Village in Changguo, Zhangbazhai Village in Yangerzhuang, and Yunzhuang Village in Jiucheng Town. In total, 134 strains were obtained by isolation and cultivation from soil samples. Of these strains, 30 were chosen based on the growth promotion of M. sativa seedlings after 60 days of incubation. We also compared the performance of the strains based on their phosphate solubilization and auxin secretion abilities. The result showed that the strain EF2 had a significant positive influence on plant dry weight, and it also had the strongest phosphate solubilization ability, whereasthe strain LF13 hadthe strongestinfluenceon plant height, and also had the strongest auxin secretion ability. In conclusion, we obtained nine highly effective strains by investigating the ability of phosphate solubilization and auxin secretion, as well as growth promotion.