Effects Of Water And Salt Stress On Peanut Growth And Physiological Characteristics

To solve the problem of drought or waterlogging stress faced in saline, the present experiment with Huayu20 and Huayu36 as materials was carried out to study the relationship between peanut growth and the affects of water and salt stress in stage of florescence. By figuring out the change including photosynthesis, agronomic traits, dry matter accumulation, osmolytes, antioxidant enzyme and yield of different flowering water stress after 10 days and rehydration after 10 days under different salt concentrations, which can provide fundamental theories for the problem of drought or waterlogging stress facing in salinity.1. At non-salt concentration, compared with normal irrigation, peanut proline(Pro) content of HY20 increased by 144.39% and 144.39% under moderate and mild drought stress. Soluble protein(Pr) content increased by 25.95% and 25.95%. Soluble sugar(SS) content increased by 18.10% and 8.89%. Malondialdehyde(MDA) content increased by 28.80% and 28.80%. Superoxide anion radicals(O2-) increased by 217.57% and 38.85%. Activity of Superoxide dismutase(SOD) decreased 14.21% and 3.09%. Catalase(CAT) activity by 44.29% and 44.29%. Net photosynthetic rate reduced by 114.71% and 51.28%. At the same time, main stem height, leaf area, plant dry matter weight, the first lateral branch length and leaf relative water content decreased. Water returned to normal after 10 days, the difference of the first lateral branch length, osmotic regulation substances, main stem height, dry matter accumulation was narrow. After harvest, each treatment of HY20 and HY36 has the highest yield of normal irrigation and 90% irrigation. After 10 days in rehydration, SOD and POD activity raised a little compared with normal watering. Yield of normal watering was highest, 90% irrigation treatment followed in HY20 and HY36.2. At 0.15% salt stress concentration, compared to normal watering, after double flowering water and salt stress treatment for 10 days, the main stem height, first branch length, relative water content, leaf area, net photosynthetic rate decreased under moderate drought and mild drought stress, increased the content of proline, soluble protein, soluble sugar, malondialdehyde(MDA), superoxide anion radical(O2-) and decreased SOD, CAT, POD activity. 90% irrigation compared with normal irrigation. MDA content decreased 12.53%. O2- content decreased by 6.87%. SOD, POD and CAT activity increased by 1.98%, 2.98% and 7.95% respectively. At the same time, the first lateral branch length and main stem height was higher than normal. Water returned to normal after 10 days, content of SS, Pr, Pro increased under waterlogging stress.3. At 0.30% salt stress concentration, after double stress of water and salt stress for 10 days, the tendency of main stem height, first branch length, dry matter accumulation, net photosynthetic rate, leaf area from better to less was Waterlogging treatment> 90% irrigation> Normal watering> Mild drought> Moderate drought. Moderate drought and mild drought increased the relative water content and the content of proline, soluble protein, soluble sugar, malondialdehyde(MDA) and superoxide anion radical(O2-), but SOD, POD, CAT activity did not change significantly. Rehydration after 10 days, the contents of the soluble protein, soluble sugar increased slightly. The tendency of SOD and CAT activity from better to less was Waterlogging treatment> 90% irrigation> Normal watering> Mild drought> Moderate drought.4. Water and salt existed significant interaction among SOD CAT and Pn. Joint action of both drought and salt stress decreased inhibition of the growth of peanuts. In 0.30% salt concentration, due to the interaction of water and salt stress, waterlogging can weaken inhibition of salt stress on growth of peanut.