Effect of silicon on chlorophyll content and gas exchange characteristics of switchgrass under NaCl stress

• Jing Li, 
• Yan Yan, 
• Tao-shu Wei, 
• Lu Zhao, 
• Rong-rong Ren, 
• Yuan-yuan Qu, 
• Tian-ming Hu, 
• Ming-xiu Long, 
• Shu-bin He