| Simulation drought stress experiment was conducted to investigatemorphological, physiological and biochemical indexes in the corn seeding and studydrought resistance water-saving using Zhengdan958, Zhongke11, Xundan20andXundan22as materials. While pool planted and field deficit supplemental irrigationexperiments were performed to make a study of the effects of supplemental irrigationon photosynthesis, material production, and water use efficiency of maize, and thedrought-tolerant and water-saving of the varieties were investigated. The main resultsare as follows:1. Maize seedling under simulate drought stress conditions, In the16measuredindicators, there were ten indicators:POD，leaf relative water content. dry weight ofembryonic bud, germination rate, dry weight of root, root-shoot ratio, embryonic rootlength, embryonic bud length, germination vigor, and transformation rate can be usedas preliminary indicators of maize seedling Drought Resistance evaluation, in whichactivity of POD，leaf relative water content, and dry weight of embryonic bud can beused as the most effective indicators of maize seedling Drought Resistance evaluation.Cultivars performance on drought resistance is Zhongke11>Zhengdan958andXundan20>Xundan22.2. In the T1treatment, there was no significant difference among Pn, Tr, Gs, Ci andCK of the four varieties leaves, it can be caused by moderate supplemental irrigationwhich abated delayed action of silking stage in the early growth stage, it may also bedue to the rainfall before silking; In the T0treatment, stomatal limitation was the keyfactor leading to Pn of strong drought-tolerant varieties to decline. With the reductionof the amount for supplemental irrigation, corn in the lower part of the Pn more at thesame time to reduce the Tr, improve the leaf water use efficiency (LWUE),drought-tolerant varieties leaf water use efficiency (LWUE) is higher. It is thus clearthat drought-tolerant varieties response and adapt to changing environment mainlythrough the control of stomatal opening. In the normal irrigation treatment, Fo andFv/Fm varieties showed little differences, fundamental maintained the same level.With the reduction of irrigation, Fo increases slightly between the treatments, Fv/Fm declined somewhat, but there were not significant, the results showed that thephotosynthetic institutions were not broken under the condition of not destruction.With the reduction of amount for irrigation, qP of the four varieties decreased, theproportion of PS Ⅱ response center reduced, which lead to the ability of PSⅡelectronic transmission reducing. Under the condition of water deficit, photochemicalquenches coefficient (NPQ) increased, the smaller NPQ determination value, thestronger the drought-tolerant varieties.3. Summer maize in water deficit condition, the upper nutrition organ dry matteraccumulation quantity and the economic yield were all reduced. In Rainy year, deficitirrigation favored the nutritive organ to transport dry matter outside and promotedeconomic yield formation. by deficit irrigation, yield of Xundan22reduced most andstability is bad. Zhengdan958and Xundan20get a high and stable yield. Zhongke11had a least yield loss and showed a excellent stability. On abnormal weatherconditions, moderate deficit supplemental irrigation can play a key role in stablingyield.4. Total water consumption of maize decreased, while water use efficiency (WUE)increased with the decreasing of irrigation. Cultivars performance on total waterconsumption is: Zhongke11>Zhengdan958>Xundan20>Xundan22. So test cultivarswere divided into three types:①type of high water Consumption and highwater use:Zhengdan958and Xundan20②t ype of water-saving and high water use: Zhongke11③types of high water Consumption and low water use: Xundan22. |
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