Mitigative Effect Of Exogenous Chemical Substances On In Spinach Under NaCl Stress

Two varieties of spinach (Yinong 3966 and Ribendayuanye ) with different salt tolerance were employed to study the effect of exogenous chemical substance on spinach growth and some Physiological characteristics under the NaCl stress. Three chemical substances were employed: SA (300mg/L), ALA (Number 1:60mg/m2, Number 3: 100mg/m2, concluding PO43-) and PP333 (50mg/L). In greenhouse, the experiment had ten treatments: control (Insufflating water), CK1 (100mmol/LNaCl), T1 (CK1+SA), T2 (CK1+PP333), T3 (CK1+ALA). And the other experiment had twelve treatments: CK (Insufflating water), T (Insufflating ALA), CK1 (100mmol/LNaCl), T1 (CK1+ALA), CK2 (200mmol/LNaCl), T2 (CK2+ALA).Some Physiological characteristics were studied on two varieties of spinach under different concentrations of NaCl. The results were indicated as follows:1. SA, PP333 and ALA could alleviate the salinity of NaCl under concentration of 100mmol/L. And ALA was the best one of three, SA and PP333 was taken second place. On the prophase of growth, Insufflating ALA could increase significantly the shoot dry weight of Yinong 3966 and Ribendayuanye varieties, and were increased by 33.6% and 17.4% than CK1 respectively,and reaching at the level of natural growth. Meanwhile insufflating ALA on growth of prophase and metaphase of Yinong 3966, and of metaphase of Ribendayuanye, could decrease MDA content, and was more significant than SA and PP333. Proline content of Yinong 3966 was greatly improved by 24.04% and 47.53%, insufflating PP333 and ALA respectively, and the increasing was the most by insufflating ALA.2. Exogenous ALA could obviously alleviate the inhibition of spinaches under different NaCl concentrations of 0,100 and 200mmol/L. The yield increasing of spinach Yinong 3966 under 200mmol/L NaCl was considerably more than other treatments by insufflating ALA. However, the yield increasing of spinach Ribendayuanye under 0mmol/L NaCl was considerably more than other treatments by insufflating ALA. Meanwhile, On the different growth phases, exogenous ALA could increase spinach chlorophyll a, b content and b/a, and Proline content, soluble sugar and soluble protein content, improve root activity ,and decrease MDA content under different concentrations of NaCl, and minish spinach leaves cell membrane permeability to a small degree. The Photosynthetic rate, Transpiration rate, Stomatal conduction and Intercellular CO2 concentration of spinach were minished under NaCl stress, and photosynthesis was limited. These parameters were increased to different degree, and photosynthesis was improved insufflating ALA.Obviously, all of SA, PP333 and ALA could relieve the stress of NaCl, exogenous ALA was favorable for its better physiological characteristics, and had the potential for improving resistance to salt injury, and lessened the damage the NaCl Stress on spinach growth.