The Study On Response Mechanism Of Wheat Seedlings To Salt-alkali Stress And The Relieving Effects By Exogenous GA₃

Soil salinization plays an important role in limiting agricultural production and influencing ecological environment. The plant of physiological response mechanism in salinity-alkalinity stress and how to improve alkali ability are key point for a long time. Wheat belongs to gramineous wheat genera, which acreage and output are the most in the world among annual food crops. In our country, wheat presents very important part in national economy which inferior to rice. Wheat includes many varieties, and most of them have the quality of salt tolerance. Thus, studying physiological response mechanism in Salinity-alkalinity stress and how to improve alkali ability have very important significance in agricultural production.Two kinds of carton steel Na₂SO₄ and NaCl, two alkali salts by 9:1 Na₂CO₃ NaHCO₃, the molar ratio of both mixing, setting three gradients of 0, 40, 80, 120 mmol L^-1, to explore the wheat seedlings were processing two stresses on wheat seedling long effect and physiological response mechanism. The results of the study showed that, the inhibiting effects of alkali stress on wheat seedling was greater than salt stress, and salinity-alkalinity stress root damage than its stems and leaves higher role. Wheat to salt stress and alkali intimidated physiological response mechanism are different. Making Na⁺, soluble sugar, and proline, etc are involved in salt and alkali solute the penetration of intimidation adjust action, but their accumulation of different, alkali intimidation of accumulated more than salt stress making Na⁺, soluble sugar and less of proline. Under salt stress, wheat main accumulated Cl^– and other inorganic anion balance of excessive sodium ions in alkali stress, high pH of inorganic anions restrained root absorb organic synthesis, wheat as organic anion participation ions balance function. Organic acid and Cl^– accumulation under two stresses is the physiological response mechanism and adapting strategies of wheat in the fundamental difference from alkali stress, organic acid is wheat coercion of special response substances.100mmol L^–1 of the mixture of carton steel (NaCl: Na₂SO₄= 9:1) and mixed alkaline salt (NaHCO₃: Na₂CO₃ = 9:1) stress on wheat, while handling exogenous GA₃) foliar spraying processing. Two gradients of 50ppm and 100ppm were set, research and different concentrations of exogenous GA₃ to salinity-alkalinity stress damage mitigation action. The results showed that exogenous GA₃ can effectively relieved salt stress and alkali stress on wheat seedling damage effects. Under salt stress, exogenous GA3 reduced stem leaves in making Cl^–and proline contents, which increased the stem, effective relieve suggested heavy salt stress on the growth of wheat the ground part inhibition. In alkali stress and exogenous GA3 reduce its stems and leaves of proline and making the content of organic acid, increased the content of soluble sugar, which increased the stems, and effectively relieve heavy suggested the alkali stress on wheat seedling damage effect. No matter which kind of intimidation, GA3 are suppressed stress proline accumulation products.