Effects of Salt Stress on Oat Seedling Growth and Selective Absorption of K~+ and Na~+ and Photosynthetic Characters

The pot plant experiment were conducted with different salt(NaCl and Na2SO4) concentration.The plant growth under salt stress were obviously inhibited,the order was plant height leaf area per plant dry weight per plant;The contents of chlorophyll(Chl) showed downtrend with the increase of salt content,less than salt concentration 0.3% it was decreased faster than high salt stress,the effect of chlorophyll b under salt stress is stranger than chlorophyll a;Oat seedling have selective absorption to ion transportation,root can storage Na+ and stem can storage K+,each organ's K+ content decreased and Na+ increased gradually with the strengthen of salt stress,amplitude variation order was leaf stem root.Over 0.6% salt concentration oat seedling lost selective absorption to ion.Net photosynthetic rate(Pn)and water use efficiency(WUE) showed downtrend under salt stress,the changing trend of trendstomatal conductance(Gs) and transpiration rate(Tr) and intercellular CO2 concentration(Ci) was increased at low salt and decreased at high salt stress.Salt concentration 0.2% can improve oat seedling growth and photosynthetic characters;Salt concentration 0.3% can increase the endurances;More than salt concentration 0.3% oat seedling physiological was metabolism significantly influenced;More than salt concentration 0.5% photosynthetic was hindered and growth was seriously inhibited.