The Study On The Difference Of Responses Mechanism Of Maize Seedings To Drought Stress And Nitrogen Dificiency

Drought stress and nitrogen deficiency are major factors limiting plantgrowth in the arid and aemiarid areas. Maize is great of water demand andsensitive to nitrogen supplied. To collate the drought defying character offour maize varieties (DK, GD, ND, TPY), solution culture experiment wasintroduced. The results showed that water had an effect on maize growthand this effect were difference between varieties of maize.Under drought stress, the leaf area and biomass of shoot of maizedecreased, but relative conductivity rate of the leaves, MDA content in theleaves, the activity of SOD and POD and O₂ production rate increased.The photosynthesis, transpiration and stomatal Conductance of Leaf werealso affected under drought stress.DK was well maize breeding. It was always having good photosynthesiccharactors in 35ï¼…to 70ï¼…of field capacity. It could absorbed more N, Pand K, but its relative conductivity rate of leaves, MDA content in theleaves, and O₂ production rate were lower. Moreover, DK had higher biomass under the same water supplies. However, DK was sensitive todrought stress, since its biomass, MDA content and relative conductivityrate were affected more obviously by drought stress. TPY was opposite toDK since the stress had little effect on it. The sensitivity to drought stress inND and GD were between DK and TPY.DK was more sensitive to N supplied under lower N levels. Lower Nsupplied had more affect on DK than GD. Furthermore, DK's N content inold leaves and roots decreased more than GD's with the N levels decreasing.DK was tolerance to N fertilizer under higher N supplied levels, because itsboth biomass and N accumulation were higher than that in GD. DK grownbetter than GD, which might result mainly from more N absorption by DKand larger root/shoot ratio probably.The presented results suggested that although DK had good growthcharactor, it was sensitive to drought stress and low N supplied. Droughtstress had little effect on TPY, while the sensitivity of ND and GD todrought stress was similar to DK.