Study On Sodium&Potassium Uptake And Salt Tolerance Differences Of Oats In Different Genotypes

In this paper, hydroponic experiments were conducted to investigate theeffects of uptake and accumulation of Na⁺and K⁺, chlorophyll content, membranepermeability, osmotic adjustment substances under salt stress and time between4varieties of oats different in genotypes （Tybor naked oat、Marion oat2002、Nova oat2003and Bai yan-6）, which were also to explore the sodion absorption dynamics and itsexclusion laws, and study the effects of calcium and calcium chelator （EGTA） on uptakeof sodion and potassium. The main results were presented as follows:1. Compared with Tybor naked oat and Nova oat2003under salt stress, Marion oat2002and Bai yan-6have strong ability on K⁺selective absorption and retain K⁺, with thehigher K⁺/Na⁺, higher content of proline and chlorophyll content, and lower content ofMDA. The fact that Marion oat2002have the lowest content of Na⁺in deferent level ofsalt stress shows that this genotype of oat have strong ability of Na⁺exclusion. Amongthe4oats varieties, Marion oat2002and Bai yan-6were more tolerant to salt whileTybor naked oat and Nova oat2003were sensitive to salt.2. Na⁺absorption can be divided into two absorption system, the low-saltabsorption（NaCl0¹00mmolL-1） and high-salt absorption（NaCl100⁴00mmolL-1）. Inthe low-salt absorption phase, the maximum absorption rate of sodion and Michaelisconstant were low, Na⁺uptake rate is low, membrane transport proteins were high-affinitywith Na⁺. In high salt absorption stage, Na⁺maximum absorption rate were344.83and232.56μmol.g-1h-1, the Michaelis constant were481.55and265.86mmolL-1, in contrastwith the low-salt absorption, low-affinity with Na⁺at this phase, the more membranecarrier protein quantity, the higher accumulation rate of Na⁺. In addition, Marion oat2002is stronger on transpiration,lower absorption rate, higher K⁺/Na⁺and higher rates ofexclusion of Na⁺than Tybor naked oat.3. Effect of processing of CaCl2is conducive to oat plant’s dry matter weightcompared with the control. Processing of CaCl2have the higher Ca2+content, K⁺/Na⁺and Ca²⁺/Na⁺, the processing reduce the Na⁺content significantly and improve the K⁺content. The Na⁺content of Marion oat2002reduce significantly than Tybor naked oatwith the effect of CaCl2. On the contrary, processing of EGTA significantly improve the Na⁺content and reduced K⁺,Ca²⁺content and Ca²⁺/Na⁺, Tybor naked oat have high levelsof Na⁺content,and its K⁺, Ca²⁺content and Ca²⁺/Na⁺is relatively low.