The Physiological Response Of Different Wheat Materials To Salicylic Acid, Nitric Oxide And Nitrogen Nutrition Under UV-B And Cd Stresses

Adverse conditions, such as drought, salt, heavy metal cadmium and UV-B radiation and so on have a big impact on the agricultural production of wheat, to conduct how to ease the growth of wheat seedlings under adversity stress plays an important role in the physiological effects of research. Under this experiment studied the UV-B stress, dwarf polish wheat seedlings of salicylic acid and nitric oxide composite processing for photosynthesis and antioxidant capacity of the physiological response, and carried out under cadmium stress, nitrate nitrogen and ammonium nitrogen effect on the growth of J-11 and PHW-SA wheat seedling research. The main results are as follows:(1) UV-B stress significantly decreased plant height, shoot dry mass, pigment content, net photosynthetic rate, intercellular CO2 concentration, stomatal conductance, transpiration rate and Fv/Fm, but increased the content of malondialdehyde (MDA), proline, O2·- and H2O2 under UV-B stress.(2) When SA, SNP and their combination were applied, the contents of MDA and proline were significantly decreased and the accumulation of H2O2 and O2·-was considerably diminished. Moreover, there were considerable increases in activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR) under UV-B stress in the presence of SA, SNP, and their combination. The combination of SA and SNP significantly improved the photosynthetic parameters, antioxidant enzymes activity and mitigated the increased accumulation of reactive oxygen species from UV-B stress.(3) In PHW-SA, ammonium nitrogen significantly reduced cadmium accumulation in underground part of wheat seedling, but increased the cadmium accumulation of above-ground part under Cd stress. However, the cadmium accumulation trend is contrary in the J-11. A large proportion of Cd in cell wall and the cytosol were detected in J-11 and PHW-SA wheat seedling. Under cadmium stress, ammonium nitrogen decreased the percentages of cell wall and cytosol of the above-ground part, but increased the percentages of cell wall and the cytosol of underground portion. In PHW-SA, ammonium nitrogen treatment increases Cd content in cell wall and cytosol, decreases the Cd accumulation of in organelles, thus alleviate the damage under cadmium stress environment.(4) Cadmium stresses decreased biomass, total root length, lateral root length, root surface area, root volume, root diameter, photosynthetic rate and the ?15N content. Meanwhile, cadmium stresses result in nutrition element deficiency of Fe, Cu, Zn, Ca, Mg, and destroy the nutrient balance. Compared with nitrate nitrogen, ammonium nitrogen can significantly improve biomass accumulation, total root length, lateral root length, root surface area, root volume, root diameter and the ?15N content in PHW-SA wheat seedling, but the nitrate nitrogen treatment is better for J-11. Ammonium nitrogen can significantly improve Fe and Ca content in PHW-SA. Under the same nitrogen form condition, the ?15N content of PHW-SA are significantly higher than that of J-11. These results indicated that the genetic transfer from related species to wheat may be changed the absorption and use bias of nitrogen form in wheat, increased the nitrogen use efficiency, help PHW-SA to acclimate to the cadmium constraint.