Evaluation of physiological response and cold resistance of four alfalfa cultivars to low temperature stress

• ZHAO Yihang, 
• MENG Lingdong, 
• ZHANG Xiaomeng, 
• WANG Li'na, 
• LIU Haoyue, 
• BI Linlin, 
• LIU Hongliang, 
• YIN Xiujie