Soil Water Contents And Antitranspirant On Stomatal Development And Phsiological Metabolism Of Maize

The shortage of water resource limited the development of agriculture. 95% of water absorbed by roots lost out through stoma on the leaves. So it is a good way to increase the water efficiency in plants and save irrigation water through adjusting stoma open or reducing transpiration water consumption. In this study, potted maize was subjected to three grades of soil water contents and sprayed commercial antistranspitant. The three kinds of soil water treatment conditions were adopted with the maximum field capacity for holding water being 70%, 60% and 50%. We observed and compared stoma density, stoma open, stoma length and width of new developing leaves, and assayed stomatal morphology, photosynthetic indexes, physiological indexes, water transpiration consumption and biomass under different soil water contents and antistranspirant. The results indicated that,(1) Stoma density increased along with leaf area increases until maximum value in the early period of leaves development. The stoma totalities had been growing in the whole stage. The changes of stoma length and width were small in seeding stage, the length of stoma increased slowly but the changes of width were not obvious in the whole stage.(2) The decreased of soil water contents led to an increase of stoma density and a decrease of stoma open, length and width. The reduction of stoma width was more significant than the length. Stoma open decreased was attributed to the lesson of stoma width.(3) If soil water contents decreased, the transpiration rate would descended before the photosynthetic rate. The most remarkable performance was stoma open decreased along with a sharp drop of the transpiration rate, whereas the photosynthetic rate decreased insignificantly. Then it appeared the case of water consumption reduced.(4) With the decreased of soil water contents, the membrane permeability, MDA contents, soluble sugar contents increased, but the chlorophyll contents and leaves water retention decreased. The plants height showed differences among three soil water contents and had maximum differences after trumpeting stage.(5) The orders of water transpiration consumption under normal water conditions were proved to be: filling stage>tasseling stage>jointing stage>seeding stage; the average daily water consumption showed that: tasseling stage>filling stage>jointing stage>seeding stage; The daily water consumption in tasseling stage was the maximum. So agricultural production should ensure the water supply in tasseling-silking stage firstly and carry out quantitative irrigation according to water requirement in different development stages.The water consumption in maize whole life was decreased with the increasing degree of water stress, the plants needs 20.00 kg, 16.74 kg and 12.62 kg water respectively under three soil water conditions. The results indicated that mild soil water stress increased the water use efficiency in the case of reduction of water consumption, whereas has no obvious influence on stoma or corn yield; the medium water stress decreased water consumption, WUE and yield significantly. Therefore we could reduce soil water content appropriately in agricultural production in order to attain the purpose of water-saving.(6) Spayed antitranspirant on maize leaves obviously reduced the bad effects on stoma under water stress and decreased water transpiration consumption. The effects were more and more obvious along with usage amounts increased. After sprayed antitranspirant on leaves, the plants increased photosynthetic rate and yields through increasing chlorophyll contents or decreased the degradation rate under drought stress. The effects was more significant in tasseling stage and filling stage, and it is most prominent in filling stage under normal water supply, but the using of times and amount needs further research.Our subject offered the research significance in water-saving agricultural field. Firstly, we could reduce soil water content appropriately and carry out quantitative irrigation according to water requirement in different development stages in order to improve the water efficiency. Secondly, we could use the antitranspirant to decrease water consumption, but the amount and the concentration require further study. Lastly, we could adjust stomatal development process under water drought in early period in order to save water, maintain a high photosynthetic rate and improved water use efficiency.