The Affection Of Exogenous ALA,SA,CaCl₂ On Physiological Characteristic Of Lettuce Under Salt Stress

Soil salinization is an important factor that can affect crop growth. How to settle soil salinization has become a significant problem, which is not only international, but also wrgency in biological technology. The trait of agritechnology is adopting man-made measure to alter pary environment, which will greatly improve the yield and quality of vegetable .But because it's not very scientific of culture, water and fertilizer, the phenomenon of salinity accumulation is so apparent. That causes soil salinization of sheltered farmland, which severely affects the production.On the basis of the research on mitigative effects of exogenous materials in the vegetation under salt stress , the experiment simulates salinity of soil salinization Lettuce(Lactuca sativa var.capitata L.) was used to study the effects of exogenous materials,the lettuce(salt-tolerant:Xiang gang bo li sheng cai;Salt-sensitive:Mei Guo da su sheng)as the marterial in the experiment. SA, CaCl2 and AlA were Spurting as the different treatments and Spurting water as the CK. The Lettuce growth and antioxidation protective and physiological metabolism were studied in the experiment and the main results as follows:1. The effect of Exogenous ALA, SA, CaCl2 on physiological characteristics of Lettuce under Salt Stress.For the salt-tolerant Variety-Xiang Gang bo li sheng cai: the single yield was increased by 50.1% than CK under non-salty stress after used exogenous ALA; The conductivity was reduced, the content of chlorophyll and solution protein,root activity was increased after used Exogenous ALA; And the content of chlorophyll was increased after used Exogenous CaCl2.For the Salt-sensitive variety-Mei Guo da su sheng: the single yield was increased by 69.5% than CK under 100mmol/L NaCl stress after used exogenous ALA; The conductivity was reduced, the content of solution protein, root activity was increased after used Exogenous ALA; And the conductivity was reduced, the content of chlorophyll was increased after used Exogenous SA; The root activity was increased after used Exogenous CaCl2. In a word, ALA of the three Exogenous materials has the best effect of Mitigative effact of salt stress with increased the yield and changed plant shape, physiological and biochemical characteristic than SA and CaCl2.2. Mitigative Effect of Exogenous ALA on Lettuce under salt stress. For the salt-tolerant Variety-Xiang Gang bo li sheng cai: the yield was increased by 32.6%, 16.7%, 29.8%, 34.5% than CK under 0～150mmol/L concentration of NaCl stress after used exogenous ALA; For the Salt-sensitive variety-Mei Guo da su sheng: the yield was increased by 20.9%,11.5%,62.4%,25.7% than CK under 0～150mmol/L concentration of NaCl stress after used exogenous ALA. The conductivity reduced, so the salt stress was weakened with ALA, and the effect of ALA was better in the later stage of lettuce grown. The content of MDA under 100mmol/L concentration of NaCl stress, and the effect was notable in the later stage of grown. Antioxidation protective was also changed after used ALA, the SOD activity increased with ALA treated in the later stage of grown for salt-tolerant variety under high salt stress, but it has better action for Salt-sensitive variety under low salt stress. The CAT activity increased with ALA treated for salt-tolerant Variety under 50mmol/L and 100mmol/L concentration of NaCl stress. The POD activity increased with ALA treated for salt-tolerant Variety under 0～100mmol/L concentration of NaCl stress, and ALA had notable affect of salt-sensitive variety under 100mmol/L concentration of NaCl. The content of chlorophyll and the quality of vegetables were increased after treated used ALA In a word, the yield increased, plant shape improved,physiological characteristic changed and vegetable quality increased with ALA treated, and in the later stage under 0～100mmol/L concentration of NaCl with ALA treated had better effects.