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

• Xing-yue Wu, 
• Hong-li Yao, 
• Bei-nan Wang, 
• Xue-yin Bao, 
• Peng-fei Liu, 
• Zhong-kuan Liu, 
• Wei-dong Cao, 
• Xiao-yun Liu