Effect Of Lanthanum Nitrate On Seed Germination,Seedling Growth And Cold Resistance Of Wild Bromus Catharticus (Bromus Catharticus)

Wild Bromus Catharticus is a short-term perennial fine forage grass that can keep green and frost-resistant in winter.Lanthanum nitrate can affect the growth and development of many plants and improve their resistance,but it is not clear whether there is any effect on the seed germination,seedling growth and cold resistance of Wild Bromus Catharticus.This study with Wild Bromus Catharticus as research materials,through germination test,measured the germination and seedling growth of related indexes;the leaves were sprayed with different concentrations of lanthanum nitrate for 4 days,then the phoysiological indexes on the ground was determined under low temperature stress?-5??at different time.The results included:1.3.5×10-3mg/L concentration of La?NO₃?₃ soaking,can improve the wild Bromus cartharticus seed vigor and maintain consistency of emergence.2.Different concentration of lanthanum nitrate treatments on seedling length,root shoot ratio,leaf area and fresh weight of wild Bromus cartharticus had no significant effect,5.7×10-3mg/L La?NO₃?₃ treatment can promote the root growth.3.With 2.3×10-3?3.5×10-3?4.6×10-3?5.7×10-3mg/L in the concentration of La?NO₃?₃solution soaked,the cell membrane permeability of wild Bromus cartharticus seedlings can be decreased.4.100mg/L lanthanum nitrate treatment of wild Bromus cartharticus SOD activity significantly increased at-5 ? for 72 h,and different concentrations of lanthanum nitrate treatment had no significant effect on the change of wild Bromus cartharticus POD activity.5.At-5? under low temperature stress,lanthanum nitrate treatment could suppress the soluble sugar content of wild Bromus cartharticus.6.At-5 ? under low temperature stress,MDA content decreased with different concentration of lanthanum nitrate treated,shows that spraying lanthanum nitrate on the leaf could reduce the damage of MDA to the cell membrane of wild Bromus cartharticus under low temperature stress.The above results show that: 3.5×10-3mg/L concentration of lanthanum nitrate seed treatment can improve the wild Bromus cartharticus seed vigor and germination;5.7×10-3mg/L concentration of lanthanum nitrate seed treatment can improve the wild Bromus cartharticus seedling root growth,and reduce seedling membrane permeability,then protective cell membrane.At-5? low temperature stress conditions,with the stress intensity increased,lanthanum nitrate treatment can improve wild Bromus cartharticus activity of SOD,decrease the content of MDA,can improve the cold resistance.