Effects of salt and alkali interaction stress on chlorophyll fluorescence in leaves of Sorghum bicolor×S. sudanense

• Wei-wei Jin, 
• Hui-hui Zhang, 
• Zhi-yuan Teng, 
• Xiang-xin-yue Meng, 
• Shu-bo Zhang, 
• Xiu-li Zhang, 
• Nan Xu, 
• Guang-yu Sun