Effects Of Water Deficit On Maize Physiology, Morphology And Anatomical Structure

The shortage of water resources seriously restricted the development of agriculture in our country. Researching the influence of corn growth under moderate water deficit and compensation effect can ensure the appropriate irrigation.It is a fundamental way of saving water and developping sustainable agriculture.We make water control experiment by planting crop GaoNong 901 in pots,using spectrophotometer, tissue stain , scanning electron microscope and ordinary optical microscope,to determine different growth stages(seedling stage,elongation stage) of different water deficit of corn physiological indexes and observe morphological properties and anatomical structure. The effect of different water deficits: 75%-85%(control), 65%-75%(LS), 55%-65%(MS), 45%-55%(SS)of soil moisture capacity.(1)The influence of Water deficit on physiological indexes: with the degree of seedling water deficit aggravating , super oxide anion radical, soluble protein, proline and POD activity elevated. SOD,CAT activity presented to rise first and then drop. The change of super oxide anion radical, proline , SOD,CAT activity in the jointing stage were similar to seedling stage,but soluble protein and POD activity presented to rise first and then drop . With the degree of seedling water deficit aggravating ,the ABA content of root and leaf,and seedling stage growth rate is larger than jointing stage.The change of H2O2 is same to ABA,the change of ABA and H2O2with respect to the change of stomatal had negative correlation.(2)The influence of Water deficit on the morphological indexes:Water deficits in Seeding stage and in elongation stage are both keeping down the grow of plant height, expansion of leaf area, when rewater in Seeding stage, plant height and leaf area emerged Varying degrees of Compensation effect, especially in seeding stage.By the end of period of duration,mild wane and moderate wane started overcompensation. Implementing severe water deficit during shootingperiod was an inhibition to the merisis of the agric, also leaf area and plant height didn't return to normal level after recuperating. Implementing water deficit during seedling stage, as the aggravation of the water deficit degree, we can see that the length of root system became shorter, the diam of root became more slender, total biomass reduced, yet the root/shoot ratio increased, the density and the total length of root hair reached the maximum under the condition which was moderate water deficit wane. Root hair will get inhibited and damaged under overdrought condition.(3)The influence of water deficit on root anatomic structure and root polysaccharide: root anatomic structure changes under the water deficit of seedling. With the decrease of water in the soil, the number of vessel changes little, but the vessel wall became irregular under water deficiency . the decrease of vessel diameter caused the decrease of central cylinder area. When the soil regains enough water, the changed vessel becomes normal again. If the water deficit is very serious, recovery was litter. During the seedling, water deficit in the soil leads to the increase of root apex polysaccharide .Polysaccharide mainly increased in the epidermal cells and pileorhiza cells. In the epidermis cells, polysaccharide mainly occurred as dissociation, while pileorhiza cells mainly occurred as starch grains.In short, water deficit inhibited the growth of plants ,when water deficit, plant can activate the anti-oxidization system in the body to eliminate free radicals under water deficit. maize increase the content of ABA, and promote of the closure of stomatal ,then reduced water loss. And through its own osmotic adjustment to maintain a low osmotic potential, and increase water holding capacity, the drought resistance strengthened. Proper water deficit has compensation effect, even a super compensation, excessive deficit compensation is not apparent, even a loss.