In order to determine best irrigation mode, it is necessary to research on water stress aftereffects to corn yield and senescence in the early corn growth stage. By pot and plot experiments, the results show that moderate rewatering after water stress in initial corn growing season can preserve large photosynthetic area, keep photosynthetic system activity, delay chlorophyll degradation and enable functional leaves to maintain high photosynthetic efficiency, which is eventually beneficial to dry matter accumulation during final growing season of corn. It proves that the post-drought rewatering in the initial corn growing stage has obvious aftereffects. Particularly, the aftereffects are significant after water stress at late stage of seedlings and short-duration light drought at early jointing stage.

为了确定最佳的灌水模式，有必要对前期水分胁迫对玉米生育后期衰老及产量的后效性进行研究，该文通过盆栽和小区试验，得到以下结果：前期适度的胁迫后复水使玉米后期保持了较大的光合面积、维持了光合系统的活性、缓解了衰老过程中质膜的氧化作用，降低了叶绿素降解速度，使功能叶在生育后期维持了较高的光合效率，有利于干物质累积和产量的提高。说明玉米前期旱后复水后效性明显，尤以苗后期胁迫、拔节初期短历时轻旱后效性最佳。

The theory and technology of water-saving through crop compensation for water deficit and how they relate to crop production are theoretically important and potentially promising in agriculture application. Molecular and physiological mechanisms, however, still constitute those issues that need further research. The molecular and physiological processes of water-saving of crop by compensation for moderate water deficit was systematically analyzed based on related research advances in recent years. The researches results showed that water deficit and re-watering could change growth of plant nutritional organs such as roots, stems and leaves. Osmo-regulation, transpiration, photosynthesis and other physiological processes were also altered by water deficit and re-watering. Protein activity and molecular metabolism of crops adapted to changes in water availability. A water deficit threshold controlled compensations in crop production. With appropriate degree and duration of water deficit, crop water use efficiency improved and even increased (instead of decreasing) crop yield. If widely adopted in agricultural production, water-saving technologies through compensation for water deficit could be vital for improving economic returns and food safety.

作物缺水补偿节水理论及其技术具有重要理论意义和农业应用潜力, 受到国内外专家的重视并取得一系列重要研究成果, 然而作物适度胁迫缺水产生补偿节水效应的分子生理机制却仍是一个尚待研究的问题。在系统总结近年来的相关进展基础上, 对引起作物适度缺水反弹补偿节水的分子生理过程进行了初步分析探索。作物在发生水分胁迫和复水后, 在根、茎、叶等营养器官生长、渗透调节、蒸腾速率、光合作用等生理活动以及蛋白质活性、生化代谢、分子和基因调节等方面都有相关适应变化。水分亏缺补偿存在阈值范围, 如果控制适当, 在一定水分亏缺强度范围内可提高作物水分利用效率并使作物不减产甚至增产。这种缺水补偿节水技术如能在农业生产上推广应用, 可有效节约水资源, 提高作物经济效益和粮食安全。

Effect of regulated deficit irrigation (RDI) conducted in seeding stage of maize on the physiological status and water requirement was studied in the paper based on field experiment in Huoquan Irrigation District, Shanxi Province during 2 growing seasons. The results indicated that RDI could postpone leaf senescence and increase photosynthesis rate, transpiration rate and root activity in later stage. Photosynthesis rate and transpiration rate were lower than those of control treatment after recovering of water in jointing and heading stage,but higher in filling stage. Water consumption in seeding stage, jointing stage and heading stage under RDI were less than those of the control treatment but more in filling stage. Total water requirements during the whole growing season under RDI were less.

以玉米为试验材料,根据山西省洪洞县2年大田试验结果,研究了玉米苗期调亏处理对后期生理性状及需水规律的影响。结果表明玉米苗期调亏处理能延缓后期叶片和根系衰老,保持较高的光合速率、蒸腾速率和根系活力。复水后拔节期及抽雄期叶片光合速率、蒸腾速率和作物需水量均比对照有所下降,而在灌浆期较高。作物总需水量减少

With the highyielding winter wheat cultivar Jimai 22 as test material, a field experiment was conducted in Yanzhou of Shandong to examine the effects of regulated deficit irrigation on the water consumption and water use efficiency（WUE）of the cultivar. Five treatments were installed,  i.e ., the soil relative moisture content at sowing, jointing, and anthesis stages being 80%, 65% and 65% (W0 ), 80%, 70% and 70% (W1), 80%, 80% and 80% (W 2 ), 90%，80% and 80% (W 3 ), and 90%, 85% and 85%  (W 4 )， respectively. Under the condition of 228 mm precipitation in growth season, the total water consumption was higher in treatments W 1 and W 4 than in treatments W 0 , W 2 , and W 3 , and no difference was observed between treatments W 1 and W 4 . Comparing with W 4 , treatment W 1 decreased the water storage in 0-200 cm soil layer and the water consumption by wheat from jointing to anthesis stages, but increased the water consumption from anthesis to maturity stages. The water consumption rates at the stages from jointing to anthesis and from anthesis to maturity in treatment W 4 were higher. Under regulated deficit irrigation, treatment W 0 had higher WUE, but the grain yield was the lowest. The WUE in other treatments increased first, and then decreased with increasing irrigation amount. Both the water consumption and the grain yield were the highest in treatments W 1 and W 4 , and treatment W 1 had higher irrigation water use efficiency and irrigation benefit than treatment W 4 , being the best irrigation regime of high-yielding and water-saving in our study.

以高产中筋冬小麦品种济麦22为材料，在山东兖州小孟镇史王村进行田间试验，研究了调亏灌溉对冬小麦耗水特性和水分利用效率的影响.结果表明：在全生育期降水228 mm条件下，W 1 （土壤相对含水量：播种期80%+拔节期70%+开花期70%）和W 4 （土壤相对含水量：播种期90%+拔节期85%+开花期85%）处理总耗水量高于W 0 （土壤相对含水量：播种期80%+拔节期65%+开花期65%）、W 2 （土壤相对含水量：播种期80%+拔节期80%+开花期80%）和W 3 （土壤相对含水量：播种期90%+拔节期80%+开花期80%）处理，W 1 和W 4 处理间无显著差异；W 1 处理增加了0～200 cm土层土壤贮水消耗量，降低了小麦拔节至开花期的耗水模系数，提高了开花至成熟期的耗水模系数；W 4 处理在开花至成熟期、拔节至开花期的耗水量和耗水模系数均较大.调亏灌溉条件下，W 0 处理水分利用效率较高，但产量最低；随灌溉量增加，其他处理水分利用效率呈先增加后降低的趋势.耗水量最高的W 1 和W 4 处理产量也最高，W 1 处理灌溉水利用效率和灌溉效益均高于W 4 处理，为本试验条件下高产节水的最佳处理.

摘　要： 为探讨在干旱胁迫及复水条件下,植物对体内水分运输过程的调控能力,以盆栽2年生刺槐苗木为材料,用改良的＂冲洗法＂测定了干旱及复水处理条件下刺槐苗木体内水分运输过程参数。结果表明：1刺槐苗木水分运输过程胁迫指数随干旱胁迫程度的增大而增大,不同处理间胁迫指数均差异显著（P〈0.05）。不同时期刺槐苗木水分运输过程胁迫指数从大到小呈现为：生长初期、生长旺期、生长末期的趋势。2干旱胁迫复水24 h后,刺槐苗木水分运输过程参数均有不同程度恢复,恢复度变化随干旱胁迫程度的增加而减小,不同处理间恢复度均差异显著（P〈0.05）。3干旱胁迫复水24 h后,刺槐苗木水分运输过程存在补偿效应且主要出现在苗木的生长旺期轻度干旱胁迫条件下,补偿指数随胁迫强度的增加而下降,不同处理间差异显著（P〈0.05）。因此,干旱胁迫会对植物造成一定的伤害,然而植物为保持正常的生理活动,能够启动一系列应激反应来阻止、降低或修复干旱胁迫造成的伤害且恢复程度与苗木生长时期及干旱胁迫程度密切相关。复水24 h后,刺槐苗木水分运输过程存在明显补偿现象,这是生物保存自身的一种重要机制,弥补干旱胁迫对苗木所造成的损失。

Drought is a major limitation for plant growth, development and production worldwide. It becomes an increasingly serious problem due to global climate changes. Water deficit affects virtually every aspect of plant metabolisms. Periploca sepium Bunge ( P. sepium ) is a native and widespread shrub on the Loess Plateau, a typical drought-prone region in China. An experiment was conducted to investigate the effect of drought stress on growth, water relations, biomass partitioning, osmotic adjustment, lipid peroxidation, and oxidative enzyme activities of 2-year-old potted P. sepium plants. The plants grown under well-watered and water stressed conditions which were imposed by controlling the water supply. Results showed that the peak water consumption and fast-growing period of P. sepium plants under three different water treatments appeared the rainfall season (June to August) of the Loess hilly regions. P. sepium plants grown under the water deficit condition had much less growth rate and biomass accumulation than the plants grown under the well-watered condition. In contrast, P. sepium plants under drought condition had significantly greater root to shoot ratio and water use efficiency (WUE) than the well-watered plants. The increase in WUE with the decreases in biomass and water consumption under water stress condition seemed to be the water-saving strategy of P. sepium . The malondialdehyde (MDA) content and the membrane permeability are often used to estimate the degree of lipid peroxidation. The MDA content and the membrane permeability in leaves of P. sepium plants did not differ between the drought stress and well-watered treatments until the end of the experiment. The SOD and POD activities in the leaves increased throughout the experiment for both the well-watered and water stressed plants. Osmotic adjustment has long been proposed as an effective drought resistance mechanism of higher plants, which can help plants maintain turgor and turgor-dependent processes. Water deficit stimulated the accumulation of proline, soluble sugar and soluble proteins in P. sepium leaves under the moderate and severe drought stress conditions. The contents of these three solutes were highest under severe water stress condition and followed by those under moderate drought stress conditions. The proline and soluble sugar contents increased during the experiment, while the soluble proteins content showed an initial increase and then subsequent decrease. Our results indicate that some key physiological processes may facilitate P. sepium establishment and growth in the semi-arid and arid Loess hilly region, which include not only drought avoidant but also drought tolerant strategies. These strategies find expression in the abilities of taking the full advantage for the limit water resource, reducing transpiration, enlarging the roots for deeper soil moisture, keeping high activities of protective enzymes, and accumulating more organic solutes. As a native shrub on the Loess Plateau, therefore, P. sepium has been evolved many adaptations to counteract water deficit stress as a result of the long-term natural selection and co-evolution. This study provides useful information for vegetation restoration with P. sepium in the Loess plateau.

以黄土丘陵区常见灌木杠柳( Periploca sepium Bunge.)的两年生苗木为试验材料,模拟不同程度的土壤干旱环境,研究了土壤干旱对杠柳生长和生理生化特性的影响。结果表明,在3种土壤水分条件下杠柳的耗水和快速生长期均集中在6-8月,与黄土丘陵区雨热期重叠。在干旱胁迫下杠柳生长减慢,生物量累积减小,生物量优先向根系分配,根冠比显著增大。与适宜水分下相比,干旱胁迫下杠柳的水分利用效率随生物量与耗水量减小而显著升高,表明杠柳具有节约型水分利用对策。杠柳在干旱前期和中期丙二醛(MDA)含量下降、膜透性略有增加,干旱末期MDA含量和细胞膜透性与适宜水分相比显著升高。在中度干旱与严重干旱下,杠柳的超氧化物歧化酶与过氧化物保护酶活性持续上升直到试验末期才稍有下降。干旱胁迫对杠柳叶片渗透调节物质含量的影响显著,脯氨酸、可溶性糖和可溶性蛋白含量均随着干旱胁迫程度的加大而显著升高,且随着胁迫时间的延长,脯氨酸和可溶性糖含量一直保持上升趋势;可溶性蛋白含量在前期急剧上升,中、后期下降,但含量一直高于适宜水分处理。本研究表明,杠柳能够充分利用黄土丘陵区局部雨热资源优势、具备减少地上蒸发面积、增加地下生长、吸收深层土壤水源等御旱策略以及保持较高的抗氧化酶活性和渗透调节能力等生理学耐旱机制,本研究从生长、生理特征上揭示了杠柳在黄土高原植被自然恢复中普遍存在的原因。

Jerusalem artichoke (Nanyu 2) was used to study the effect of calcium ion on superoxide dismutase(SOD) activity, malondialdehyde(MDA) content, net photosynthetic rate, fluorescent parameters and fresh weight under NaCl stress. The results indicated that the addition of Ca 2+ did not significantly influence the growth of Jerusalem artichoke under half-strength Hoagland nutrient solution treatment but markedly protected Jerusalem artichoke leaves from oxidative damage caused by 150 mmol/L NaCl stress. Therefore, higher activity of SOD and lower content of MDA in Jerusalem artichoke leaves were maintained under salt stress. As a result, the increases in status of electron transport by PSⅡ(Fm/Fo), primary photochemical efficiency of PSⅡ(Fv/Fm), quantum efficiency of photosystem Ⅱ(φPSⅡ), photochemical quenching coefficient(qP), net photosynthetic rate(Pn) and the decrease in non-photochemical quenching coefficient(qNP) were observed under salt stress. All these were favorable to the dry matter accumulation so that the fresh weight was increased significantly. In conclusion, the addition of Ca 2+ compensated the deficient Ca 2+ induced by salt stress, made the normal metabolism and the intact cell membrane, balanced the ions absorbed and protected the photosynthetic system.

以南芋2号为材料，研究了Ca 2+ 对NaCl胁迫下菊芋叶片中超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、净光合速率(Pn)和荧光参数及菊芋鲜重的影响，探讨了Ca 2+ 在盐胁迫中的可能作用。结果表明，在1/2浓度的Hoagland营养液条件下外施10 mmol/L Ca 2+ 对菊芋的生长没有明显的影响，但在150 mmol/L NaCl胁迫条件下，外施10 mmol/L Ca 2+ 可有效防护胁迫所致的氧化损伤，从而维持较高的SOD活性，抑制脂质过氧化作用。使叶片在盐胁迫条件下，维持较高的PSⅡ的电子传递强度(Fm/Fo)、PSⅡ光化学效率(Fv/Fm)、PSⅡ量子效率(φPSⅡ)、光化学淬灭系数(qP)、Pn和较低的非光化学淬灭系数(qNP)，有利于物质积累从而使生物产量增加。这主要归因于Ca 2+ 可在一定程度上弥补盐胁迫导致Ca 2+ 亏缺造成的离子失衡，使植物维持较正常的生理活动，稳定细胞膜结构，维持体内离子吸收平衡，保护光合机构。

A pot experiment was conducted to investigate the effects of continuously drought stress(stopped watering for 0 d,2 d,4 d,…16 d,respectively) and rewatering on the growth and physiological properties of Cinnamomum camphora .The results showed that:(1)The diameter increment(Z d ) and the height increment(Z h ) were both inhibited under drought stress,Leaf relative water content(LRWC) under mild and moderate drought(stopped watering for 2-8 d and soil volumetric water content(SWC) decreased to 7%) were not significantly lower than that in control(D 0 ),but significantly lower than those under severe drought(stopped watering for more than 10 d and soil volumetric water content decreased to 3%).(2)The concentration of O -· 2 and H 2 O 2 significantly increased under severe drought stress.(3)The activities of superoxide dismutase(SOD) and peroxidase(POD) were promoted significantly during mild and moderate drought stress while catalase(CAT) activity increased significantly in severe drought stress,After rewatering for 48 h,the activities of these three enzymes decreased.(4)The contents of malondialdehyde(MDA) and proline(Pro) increased significantly under severe drought.(5)The contents of soluble protein(SP) increased dramatically under mild drought,while that of soluble sugar(SS) raised significantly under moderate drought.Both of them then did not decreased,after rewatering for 48 h.The study suggests that C.camphora saplings under mild drought maintained normal growth through ROS scavenging system and osmotic adjustment,while suffered from moderate and severe drought stress,the water physiology became deteriorated,membrane system was injured,enzyme activities affected,and at last the morphological growth and aboveground biomass were depressed by the drought stress.

通过盆栽和持续干旱处理研究了轻度干旱(持续干旱2~4 d)、中度干旱(持续干旱6~8 d)和重度干旱胁迫(持续干旱10~16 d)及复水对香樟( Cinnamomum camphora )幼树生理特性和生长的影响,为香樟育苗、造林及合理的水分管理提供理论依据。结果显示:(1)干旱胁迫下香樟幼树地径生长量(Z d )和树高生长量(Z h )受到了抑制;轻度、中度干旱处理(土壤体积含水量从正常状态下降到7%)下叶片相对含水量(LRWC)与对照差异不显著,重度干旱处理(土壤体积含水量下降到3%)下显著低于对照。(2)轻度、中度干旱处理的超氧阴离子和过氧化氢含量与对照无显著差异,重度干旱处理较对照显著上升。(3)在活性氧酶促清除系统中,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性在轻度干旱时显著上升,而过氧化氢酶(CAT)活性在重度干旱时才显著上升,在复水48 h后3种酶活性均恢复到对照水平。(4)在轻度、中度干旱处理中叶片丙二醛(MDA) 含量无显著变化,而在重度干旱下显著升高,且复水48 h后未见显著降低。(5)在渗透调节物质中,轻度干旱时可溶性蛋白(SP)含量开始显著升高,中度干旱时可溶性糖(SS)含量显著升高,重度干旱时脯氨酸(Pro)含量显著上升;复水48 h后Pro含量显著降低,而可溶性蛋白和可溶性糖含量无显著变化。研究发现,香樟幼树在轻度干旱胁迫下能通过自身抗氧化酶系统和渗透调节物质维持正常生长,而在中度和重度干旱胁迫条件下,其水分生理状况变差,膜系统遭受伤害,酶活性受到抑制,最终导致其形态生长和地上部分生物量积累受限。

摘　要： 盆栽试验结果表明，高梁和玉米2种作物均存在渗透调节和抗氧化耐旱途径。高梁耐旱性较强，干 旱条件下叶片相对含水量较高，水势亦较大。高梁以可溶性糖和蛋白质为主要渗透调节物质，以过氧化氢酶（CAT）为主要抗氧化酶。玉米以K^＋和脯氨酸为主 要渗透调节物质，以超氧化物歧化酶（SOD）和过氧化物酶（POD）为主要抗氧化酶。

为探讨大豆干旱胁迫及复水生长补偿效应和代谢补偿效应机制,建立最佳节水灌溉模式,采用盆栽称质量控水法,研究了干旱胁迫及复水对大豆生长发育、渗透调节、内源激素调节和抗氧化系统的影响。结果表明:干旱胁迫抑制株高和叶面积增长,在苗期和开花期复水天数为0时降幅分别达12.50%~39.74%、21.71%~52.87%和16.93%~36.27%、27.99%~47.80%;导致脯氨酸含量、可溶性糖含量和丙二醛含量升高,在苗期和开花期复水后天数为0的增幅分别达46.97%~131.57%、99.56%~139.37%、6.64%~22.82%和31.68%~136.30%、32.63%~184.51%、15.82%~100.75%;超氧化物歧化酶活性升高,但重度胁迫10 d处理呈降低趋势;脱落酸含量升高,赤霉素和玉米素核苷含量降低,而吲哚乙酸含量苗期呈降低趋势,开花期呈升高趋势。复水后,株高和叶面积日增长量表现出短暂快速增长,产生生长超补偿效应;中度胁迫和胁迫5 d处理各代谢指标产生等量或近等量代谢补偿效应,而重度胁迫和胁迫10 d处理产生近等量或部分代谢补偿效应。因此,干旱胁迫后复水产生补偿效应是有条件的,重度胁迫尤其是长时间重度胁迫会降低补偿效应甚至产生伤害效应。同时苗期适度干旱处理可提高开花期再次受旱的适应能力和补偿效应。