Effect of seeding rate on production performance and photosynthetic characteristics of Avena sativa cv. LENA in alpine pastoral regions

• Xue-jun Xiao, 
• Qing-ping Zhou, 
• You-jun Chen, 
• Zhong Du, 
• Xiao-ling Bai, 
• Li-hua Tian, 
• Xian-qin Peng