Waterlogging stress is one of the most common stress factors to which plants in the riparian zone and wetlands are subject. Plants will produce a series of complex physiological and metabolic changes to adapt to flooding environment. These changes are essential to whether plants can adapt to waterlogging stress and then develop the normal physiological function and growth. In this paper, we systematically studied and reviewed the physiological and metabolic changes of plants under waterlogging stress, including the changes in photosynthetic physiology such as gas exchange, photosynthetic pigment and chlorophyll fluorescence, and in malondialdehyde like antioxidant enzyme system and root carbohydrate. Finally, we analyzed the existing problem in current studies and prospected the future research direction.

水淹胁迫是河岸带和湿地植被遭受的常见逆境因子之一.植物为适应水淹环境会产生一系列复杂的生理代谢变化,这些变化对植物能否在水淹胁迫下具有正常的生理功能和进行生长发育至关重要.文中总结和评述了水淹胁迫下植物生理代谢的变化,包括植物光合生理(气体交换参数、光合色素、叶绿素荧光参数)和其他生理代谢(丙二醛、抗氧化酶系和根系碳水化合物)等变化,分析了目前研究中存在的问题,并提出展望.

摘　要： 了解狗牙根（Cynodon dactylon）和牛鞭草（Hemarthria altissima）在不同水淹地区较优的种植方式对退化湿地的植被修复具有重要意义。设置4种不同水分条件，即对照组（CK）、水淹与干旱交替组（FD）、土壤表面水淹组（FL）和全淹组（SM），4种不同的植株密度（每盆分别种植1，2，4株或12株）和2种不同的种植方式（单作和混作），研究两物种在不同水淹条件下以不同方式和密度种植时的生物量变化。结果表明，水分、种植密度和种植方式均显著影响两物种的地上生物量和总生物量（P 〈 0.05）。CK和FD条件下，以中、高密度混作的狗牙根地上生物量和总生物量与单作相比显著下降（P 〈 0.05），牛鞭草在混作方式下的生物量与单作相比有了一定提高，其中在高密度混作情况下其生物量得到显著提高（P 〈 0.05）。在FL条件下，与单作相比，中、低密度混作的狗牙根和牛鞭草生物量均具有一定的上升。全淹条件下以中、低密度混作对狗牙根地上生物量和总生物量具有显著的促进作用（P 〈 0.05），对牛鞭草无显著差异（P 〉 0.05），高密度混作方式则对两物种生物量均无显著影响（P 〉 0.05）。随着水淹程度的增加，混作对狗牙根产生的生长抑制影响逐渐减弱。在长期浅水淹的地区，采取中、低密度混作将更有利于牛鞭草和狗牙根的长期共存。在较低海拔的全淹地区，采取高密度的牛鞭草-狗牙根混作方式将是更为理想的选择。

The water level fluctuation zone (WLFZ) is the most common and important feature of regulated rivers. The fluctuation zone in Three Gorges Reservoir (TGR) since impoundment reached 175m on October 26, 2010 is large, resulting in a WLFZ of up to 30m. The TGR operating cycle has also reversed the natural hydrologic rhythm, exposing land in summer (flood season) and submerging it in winter (dry season). Research has shown that the original vegetation in the WLFZ, especially trees and shrubs, did not survive because they could not tolerate winter submergence and summer drought and herbs have become the most abundant type of vegetation, with absolute dominance by perennial herbs such as Hemarthria altissima and Cynodon dactylon. It is important to examine the ecophysiological adaption of dominant species in the WLFZ during the submergence period to provide information for effectively restoring vegetation in the WLFZ. To investigate growth and antioxidant enzyme activity of dominant plants in the WLFZ of TGR, an in situ experiment using H. altissima and C. dactylon cultivation was carried out at four water depths (0, 2, 5 and 15 m) in Kai County, Chongqing City from December, 2014 to May, 2015. All plants were cultivated in plastic pots (20cm×30cm×30cm) hung from a floating platform and the height, cover, germination number, biomass, total protein, malondiadehyde (MDA), and the enzyme activities of superoxide dismutase (SOD) and peroxidase (POD) in the root system of H. altissima and C. dactylon were measured on days 30, 60 and 180. Water quality parameters were simultaneously measured, including turbidity, illumination, temperature, conductivity, dissolved oxygen and pH. Total protein was correlated with MDA and antioxidant enzyme activities. Results show that height, cover, sprout number, biomass, total protein, enzyme activity of SOD and the MDA content of submerged H. altissima and C. dactylon were all less than for unsubmerged plants, but POD activity in the root system increased. All differences, except for biomass and MDA content, were gradually significant with the submergence water depth. The positive correlation between MDA content and SOD activity was also significant. The correlation coefficients between SOD and POD and between MDA and SOD were lowest at the water depth of 15 m, so submergence may play a role in the relationship between total protein content and antioxidant enzyme activity. Correlation coefficients among enzymes of C. dactylon were higher than those of H. altissima. These results provide insight on the physiological adaptation of herbal plants to submergence and support efforts to restore vegetation in the WLFZ of reservoirs.

探讨淹没水深对多年生草本植物狗牙根和牛鞭草生长、根系总蛋白及酶活性的影响，为三峡水库消落带人工植被恢复重建提供理论依据。2014年11月至次年5月，在重庆市开县渠口镇三峡水库消落带采用原位试验：塑料容器规格20 cm×30 cm×30 cm，生长良好的牛鞭草和狗牙根采自三峡水库消落带，带根移栽，淹没水深0、2、5、15 m，淹没时间30、60、180 d，在植物取样当天测定水环境指标，比较其高度、盖度、萌芽数及根系总蛋白和丙二醛含量、超氧化物歧化酶、过氧化物酶等抗氧化酶活性，并分析根系总蛋白含量及抗氧化酶活性的相关性。与未淹没（0 m）植物相比，淹水处理导致牛鞭草和狗牙根植物高度、盖度、萌芽数、生物量、根系总蛋白和丙二醛含量、超氧化物歧化酶活性下降，过氧化酶活性显著上升；随着水淹深度的增加，除根系过氧化物酶活性显著增加外，牛鞭草和狗牙根的高度、盖度、萌芽数及根系总蛋白含量和超氧化物歧化酶活性呈下降趋势；相关分析表明，根系丙二醛含量与超氧化物歧化酶显著正相关。水淹处理改变了根系总蛋白和抗氧化酶之间的相关性，淹没水深15 m组，根系超氧化物歧化酶与过氧化物酶、丙二醛含量与超氧化物歧化酶活性之间的相关系数最小。根系抗氧化酶活性的相关系数也有差异，狗牙根的相关系数较大。

本研究模拟三峡水库水位消涨节律,设置了水淹0、5、6、7、8和9个月共6个处理,分别测定了狗牙根(Cynodon dactylon)、牛鞭草(Hemarthria sibirica)和回头青(Pycreus globosus)3种草本植物人工种子库的种子生活力及种子蛋白质、可溶性糖和淀粉含量的变化特征,以期为三峡库区消落带生态恢复人工种子库的构建提供依据。结果表明,3种人工构建的草本植物种子库对于短期水淹均具有较好的可持续性。在经历5~6个月的水淹后,3种人工种子库的种子活力虽有一定幅度的下降,但仍保持较高的水平,其中以狗牙根种子库的种子活力最高。水淹7个月后3种草本植物种子库的种子活力都发生急剧下降,并随着水淹处理时间的延长而不断下降。水淹9个月后,狗牙根、牛鞭草和回头青种子库的种子活力与对照相比,分别下降了34.2%、43.0%和63.8%。水淹还导致3种草本植物种子库种子的蛋白质、淀粉、可溶性糖含量显著下降(P0.05),其下降幅度最大的时期均发生在水淹7个月后。相比之下,狗牙根种子库的水淹持续性最强,牛鞭草次之,回头青最弱。本研究还发现,回头青和牛鞭草种子库的种子活力与水淹时间呈显著线性负相关。同时种子库的营养物质含量与种子活力也呈线性负相关,其相关程度因物种种类而异。

水淹和干旱是限制植物生长两种常见的环境胁迫。三峡库区由于采取“冬蓄夏排”调度方式,使库区消落带水位呈现出季节性“水淹-落干”交替变化特征,生长于库区消落带的植物因此受到水淹和干旱双重胁迫。为探究库区蓄水对植物耐受干旱胁迫的影响,以当年生牛鞭草(Hemarthria altissima)和狗牙根(Cynodon dactylon)扦插苗为试验对象,设置常规供水组(CK)、表土水淹组(SF)、全淹组(TF)、常规供水-干旱组(CD)、表土水淹-干旱组(SFD)、全淹-干旱组(TFD)6个处理组,同时设置3个水分处理阶段,包括水淹阶段(阶段I)、干旱阶段(阶段II)和复水阶段(阶段III),研究不同水分处理对牛鞭草和狗牙根生长、光合生理以及营养元素含量的影响。结果表明:(1)水淹-干旱胁迫显著影响了牛鞭草和狗牙根生长以及生物量的分配。阶段I结束后,牛鞭草和狗牙根TF组的株高、基径、分枝数、叶片数、根生物量、茎生物量、叶生物量和总生物量均低于CK组;同TF组变化类似,阶段II结束后,牛鞭草和狗牙根TFD组的株高、基径、分枝数、叶片数、根生物量、茎生物量和总生物量与CK相比均降低,但CD和SFD组的株高、根生物量、茎生物量、叶生物量和总生物量相较于CK组而言,均未达到显著水平,且CD和SFD组两者之间的株高、总生物量等指标均无显著差异。复水后,牛鞭草和狗牙根的各处理组生长和生物量均有所恢复。(2)牛鞭草和狗牙根经历水淹、干旱胁迫后,其光合作用发现显著变化;水淹胁迫阶段,牛鞭草SF和TF组净光合速率、气孔限制值和水分利用效率均显著降低,胞间CO2浓度显著上升;狗牙根SF组净光合速率、气孔限制值和水分利用效率同牛鞭草变化类似。干旱胁迫阶段,牛鞭草CD和SFD组净光合速率、气孔导度、胞间CO2浓度等光合参数显著低于CK组,TFD组净光合速率、气孔导度、蒸腾速率和胞间CO2浓度等指标与CK组无显著差异;与CK相比,狗牙根CD和SFD组净光合速率、气孔导度均降低,TFD组净光合速率、气孔导度等光合指标均与CK无显著差异。复水阶段,牛鞭草和狗牙根各处理组的净光合速率、气孔导度、蒸腾速率和胞间CO2浓度等指标均与CK组无显著差异。(3)水淹-干旱胁迫也显著影响了牛鞭草和狗牙根营养元素含量。当植物遭受水淹胁迫时,牛鞭草和狗牙根根部的N、P、K、Fe、Mn含量均升高,而根Cu含量均显著下降;叶片中,牛鞭草TF组中的叶Fe、Mn含量变化趋势同根Fe、Mn含量类似,但其叶P、K、Cu含量均低于CK组。干旱阶段,牛鞭草和狗牙根TFD组平均每株的N、K、Ca、Fe、Mn含量均高于CK组,而CD和SFD组的N、K、Ca、Mg、Fe、Cu含量均与CK无显著差异。复水阶段,牛鞭草和狗牙根TF组平均每株的N、K、Mn含量均显著高于CK组,而干旱组(CD、SFD和TFD)的N、P、Fe含量与CK相比均未达到显著水平。研究表明,前期水淹并未增加牛鞭草和狗牙根对后期干旱胁迫的敏感性,牛鞭草和狗牙根对水淹和干旱胁迫良好的适应性表明这两种草本植物可以作为三峡库区消落带植被恢复重建的适宜物种。

Seasonal fluctuation of water levels is commonly found in natural and constructed wetlands and the tolerance of a plant to such fluctuation is a key factor for the composition of community and distribution of wetland species. Understanding how the growth and morphology of plant species respond to different water levels and plant densities is important to help predict their productive potential under certain environments and better manage the wetlands. In this study, Hemarthria altissima was planted at four densities (1, 2, 4 or 12 plants/pot) and four water levels were imposed (Control, CK; Wet-dry alternation group, FD; Waterlogged group, LF; Flooded group, FL) to study the morphological and growth responses. The growth and morphological characteristics of H. altissima were influenced significantly by different water levels and densities. Growth was inhibited significantly in the FL group, while in the FD and LF groups, the total biomass, aboveground biomass and stem biomass of the plants were high, except in the groups planted at higher densities and there was no significant effect of densities under LF. The length of internodes and the main stems were greatest in the LF treatment, except for the group with 1 plant/pot. With increase in plant density or in the level of water stress, the total root biomass and the number of leaves and shoots decreased gradually. Moreover, with increasing flooding stress, the relative neighbor effect and its value increased gradually, and the intensity of competition decreased, but the intraspecific interaction did not shift to facilitation. H. altissima showed the ability to adopt different strategies under different water conditions, either to escape from partial submergence by further shoot elongation or to adopt a non-elongating quiescent strategy when completely submerged. Hence, H. altissima is a suitable species for planting in the regions with varying soil water availabilities. Based on the results, higher planting densities are recommended in completely flooded areas and medium densities are suitable in the partially flooded areas or in the ecotone between terrestrial and aquatic environments.

为了解常见湿地植物牛鞭草在不同水分和种植密度条件下的生长和形态响应,将4种不同密度的植株(每盆分别种植1,2,4或12株)均置于4种不同水分条件下[对照组(CK)、水淹与干旱交替组(FD)、土壤水分饱和组(LF)、全淹组(FL)],研究其生长及形态上的变化。结果表明,不同水分及密度处理显著影响牛鞭草的生长及形态特征( P <0.05)。全淹显著抑制牛鞭草的生长( P <0.05)。非全淹条件下,除高密度组外,总生物量、地上生物量和茎生物量均保持较高水平,其中在LF条件下各密度处理间无显著差异( P >0.05)。除单独个体组外,植株的节间长和主茎长均在LF条件下达到最大值。随着水分胁迫和密度的增加,根生物量、叶片数和分枝数逐渐降低。中、高密度组的相对邻体效应值随着水分胁迫的增加而增加,植株间竞争作用逐渐减弱,但未转变为促进作用。牛鞭草在不同的水环境中可以采取不同的策略以应对,适宜在水分多变地区大量种植,在易出现深水淹地区,牛鞭草以高密度种植为佳,在浅水淹或水陆交汇处,建议以中密度方式种植。

模拟三峡库区消落带土壤水分变 化特征设置了常规生长水分条件、轻度干旱水分胁迫和水淹3个不同水分处理组,通过构建人工植被体系,对消落带适生树种枫杨(Pterocarya stenoptera C.DC.)、池杉(Taxodium ascendensBrongn)进行不同比例的配置处理,研究枫杨、池杉在不同配置和不同水分处理下的生理生化响应特征。结果表明:不同配置对枫杨和池 杉的叶绿素a、叶绿素b、SOD、POD、CAT、ASP、O2.—、脯氨酸和可溶性蛋白均没有显著影响,不同水分处理及时间对枫杨和池杉SOD、 POD、CAT、ASP、O2.—和可溶性蛋白有极显著影响。配置×水分、配置×时间以及配置×水分×时间对枫杨和池杉的叶绿素a、叶绿素b、SOD、 POD、CAT、ASP、O2.—和可溶性蛋白也没有显著影响,然而水分×时间之间的交互作用对枫杨SOD、POD、ASP和O2.—有显著影响,对池杉 SOD、CAT、ASP和脯氨酸有显著影响。本研究发现枫杨、池杉对水分逆境胁迫的生理生化响应存在差异,但都能较好地适应三峡库区消落带的水分环境。

选择广东省雷州市附城镇和珠海市淇澳岛沿海1年生无瓣海桑人工林,分别在林下混种乡土红树植物红海榄或木榄幼苗,对混交林和无瓣海桑纯林林地大型底栖动物群落进行比较,探讨无瓣海桑与乡土红树植物混交对林地大型底栖动物的影响.结果显示,混交林和无瓣海桑纯林之间大型底栖动物群落的优势种存在差异;相似性分析检验(One-Way ANOSIM)、等级聚类和非参数多变量标序结果均表明1年无瓣海桑+红海榄混交林、1年无瓣海桑+木榄混交林和1年无瓣海桑纯林之间大型底栖动物群落结构差异显著.研究还发现在无瓣海桑人工林林下混交红海榄或木榄这两种乡土红树植物,可提高林地底栖动物的生物量和物种多样性.BIOENV分析说明大型底栖动物分布与红海榄或木榄这两种混交的乡土树种的凋落物量密切相关,这进一步证实了混交乡土红树植物对林地底栖动物多样性和分布的影响.两个研究地实验结果均显示,在无瓣海桑林下种植木榄的效果要优于红海榄,表现在木榄的平均苗高、凋落物量、凋落物量占群落凋落物总量百分比和幼苗成活率均高于红海榄,其对提高林地大型底栖动物生物量和物种多样性的效果也明显优于红海榄.

The knowledge of variety mixture planting in the field on the effects of powdery mildew disease and wheat yield and quality will facilitate the utilization of variety diversity to control wheat diseases. In the 2011–2012 and 2012–2013 growing seasons, we selected eight commercial wheat varieties with large differences in genetic background and disease resistance to test the feasible pattern of variety mixture in the field. In each mixture pattern containing one (control), three, four, five, six, seven, and eight varieties, wheat plants were exposed to mixed powdery mildew isolates. The area under disease progress curve, plot yield, thousand-grain weight and crude protein content in grain were measured. For disease control, four-variety mixture pattern had the best efficacy. However, the mixture patterns with seven or more varieties exhibited also good efficacy. In the 2011–2012 growing season, 42.4% of the mixture patterns were effective with relative efficacy ranging from 1.2% to 26.8%. Meanwhile, 50.0% of the mixture patterns had the effect of yield increase (0.2–14.6%) compared with the control. In the 2012–2013 growing season, 75.0% of the mixture patterns were effective with the efficacy ranging from 1.8% to 45.4% and 71.4% of the mixture patterns resulted in increased yield (0.9–16.6%). Zhoumai 18 was the best component in mixtures having good control against powdery mildew and positive effects on grain yield and protein content. Interactions among the mixture components were also observed, and such interaction had impacts on powdery mildew controlling and wheat yield.

研究品种混种对控制小麦白粉病的效果以及对产量及蛋白质的影响, 可为利用品种多样性持续控制白粉病提供理论依据及技术支持。2011—2012和2012—2013年度选用抗病性不同、遗传背景有较大差异的8个小麦生产品种, 按每个组合3~8个品种进行田间混种, 人工接种白粉菌混合菌株, 比较品种混种对小麦白粉病的病害流行曲线下面积以及小麦产量、粗蛋白含量和千粒重的影响。结果表明, 混种组分品种的数量对防效有影响, 其中以4个品种混种的防病效果最好, 但当品种数达到7个及以上时, 混种也显示出较好的控病效果。2011—2012年度混种组合中有防效的占42.4%, 相对防效为1.2%~26.8%, 约50%的混种组合表现增产, 增产幅度为0.2%~14.6%；2012—2013年度有防治效果的组合占75.0%, 相对防效1.8%~45.4%, 约71%的混种组合表现增产, 增产范围为0.9%~16.6%。供试品种中周麦18总体表现最好, 并且与其他品种混种后对控制小麦白粉病、增加产量和粗蛋白含量均有正向效应。不同混种组分品种间存在互作, 其互作对病害控制及产量均有影响。

本研究在前期对山西矿区自然定居和人工植被群落进行广泛调查与研究的基础上,选择耐旱、耐贫瘠、适应性强的豆科草本植物紫花苜蓿(Medicago sativa L.)的3种典型种植模式为研究对象——紫花苜蓿单种(M)、紫花苜蓿+冰草(Agropyron cristatum)混种(M+A)、紫花苜蓿+早熟禾(Poa annua L.)混种(M+P),以矿区生土和熟土为供试土壤基质,温室盆栽种植2年后,设置3个水分梯度——适宜水分(T1)(对照)、中度干旱(T2)和重度干旱(T3)(分别为田间持水量的75±5%,55±5%,35±5%),进行温室控水试验,采用生化技术和Li-6400XT光合作用系统等方法,研究不同土壤基质和不同种植模式下,紫花苜蓿(单/混种)对干旱胁迫的生态适应性,主要研究内容和结果如下：(1)干旱胁迫对紫花苜蓿(单/混种)叶片水分生理特性的影响与T1相比,在T2和T3下,两种基质上紫花苜蓿(单/混种)叶片相对含水量(RWC)和叶绿素含量分别显著降低5.03%-14.10%、15.33%-25.09%；叶片相对水分亏缺(RWD)显著升高20.75%-100.28%。(2)干旱胁迫对紫花苜蓿(单/混种)抗氧化酶系统的影响与T1相比,在T2和T3下,两种基质上紫花苜蓿(单/混种)叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)活性、丙二醛(MDA)含量显著升高(p0.05)。T3下,生土上紫花苜蓿(M)的SOD和POD升幅最大,分别为39.22%和105.88%,熟土上紫花苜蓿(M+P)的SOD和POD升幅最大,分别为45.97%和119.80%；两种土壤基质上,单种紫花苜蓿(M)比混种紫花苜蓿的MDA含量高,升幅大,脂膜过氧化程度高。(3)干旱胁迫对紫花苜蓿(单/混种)光合特性的影响与T1相比,在T2和T3下,两种基质上紫花苜蓿(单/混种)的净光合速率(Pn)、蒸腾速率(Tr)、水分利用率(WUE)和气孔导度(Gs)显著降低。T3下,生土上单种紫花苜蓿(M)的Pn、Tr、Gs降幅最小,分别为59.39%、34.58%和56.04%,其WUE降幅(37.99%)略大于混种紫花苜蓿(33.84%和34.81%)；熟土上紫花苜蓿(M+P)的Pn、WUE、Gs降幅最小,分别为39.17%、17.57%和53.90%。(4)干旱胁迫对紫花苜蓿(单/混种)根际土壤酶活性的影响与T1相比,在T2和T3下,两种基质上紫花苜蓿(单/混种)根际土壤脲酶和蔗糖酶的活性显著降低(p0.05)。3个水分梯度下,生土比熟土中紫花苜蓿(单/混种)根际土壤脲酶、蔗糖酶和碱性磷酸酶的活性低。(5)紫花苜蓿(单/混种)对干旱胁迫的生态适应性评价通过隶属函数综合评价得出,生土中,中度干旱下紫花苜蓿(单/混种)的隶属度均值排序为：紫花苜蓿(M)紫花苜蓿(M+A)紫花苜蓿(M+P),重度干旱下紫花苜蓿(单/混种)的隶属度均值排序为：紫花苜蓿(M)紫花苜蓿(M+P)紫花苜蓿(M+A)；熟土中,紫花苜蓿(单/混种)的隶属度均值排序为：紫花苜蓿(M+P)紫花苜蓿(M)紫花苜蓿(M+A)。生土中单种紫花苜蓿(M)比混种抗旱性高,熟土中紫花苜蓿(M+P)比单种紫花苜蓿(M)抗旱性高。生土比熟土中紫花苜蓿(单/混种)的抗旱性低。采用系统聚类方法分析结果与隶属度均值排序一致。综上所述,从植物生理生态角度来看,在干旱缺水、土壤贫瘠的山西矿区进行植被恢复时,生土上宜采用紫花苜蓿单种模式,熟土(覆表土)上宜采用紫花苜蓿+早熟禾混种模式。

Problems in development of Duolun, a typical agriculture-animal husbandry ecotone, and its countermeasures were discussed in this paper. Economic structure was not rational in Duolun, and it should develop industry and commerce, limit the scope of agriculture and animal husbandry, and actively increase efficiency of agriculture and animal husbandry. The structure of land use was not rational, and the main countermeasures were to increase area of forestland and grassland, and decrease cultivated area. On resources use, the main countermeasures were to exploit water resource rationally and bring into play resource superiority of mutually benefits on agriculture and animal husbandry. The ecological environment construction was the foundation of the national economy for sustainable development in agriculture-animal husbandry ecotone.

研究了紫花苜蓿与醉马草两者之间的种间竞争效应，结果表明，紫花苜蓿的单株生物量、相对产量（ＲＹ）和竞争平衡指数（ＣＢ）均显著高于醉马草的对应指标，竞争效应参数相对产量总和（ＲＹＴ）显著小于１；随着各处理种植密度的增大，上述指标愈加明显。在４，８和１２株／盆密度条件下，醉马草单株总生物量比其在单种处理时对应密度下的单株生物量分别降低了３８．５％，４１．４％和５６．０％，而紫花苜蓿单株生物量在混种时降低不明显。说明紫花苜蓿对醉马草具有持续的强烈的竞争抑制作用，在长期的竞争演替中，醉马草可能被紫花苜蓿替代。

Hydro-fluctuation belt refers to neighboring zones of rivers,lakes and reservoirs that is periodically submerged and exposed with the water level.It has the ecological functions of reducing soil erosion,greening and beautifying riparian landscape,preventing soil and water pollution and the more.The habitat here is under so poor condition that there grow few adaptive plants.Investigation and research on hydro-fluctuation belt plants for screening adaptive plants can enrich plant materials for vegetation reconstruction and rehabilitation in hydro-fluctuation belt.This paper reviewed research status on Hydro-fluctuation belt plants at home and abroad.Besides,research directions were also prospected.

消落带是指河流、湖泊、水库周边等因周期性水位涨落而被淹没和出露成陆的区域。消落带植被具有防止水土流失,绿化、美化河岸景观,减少水体污染等多种功能。消落带生境条件恶劣,适生植物较少,通过对消落带植物的调查和研究,筛选适生消落带植物,可以丰富消落带植被重建与恢复的植物材料。文中综述了国内外消落带适生植物的研究现状,并对未来研究方向进行了展望。

Vegetation reconstruction and restoration in the newly formed water-level-fluctuation zone(WLFZ),an anthropogenic-impacted ecosystem,is of great significance in ecological safety in the Three Gorges Reservoir Area of the Yangtze River.Selection of appropriate plant species that are adaptive to long-time and deep submergence is crucial for vegetation reconstruction and restoration in the water-level-fluctuation zone(WLFZ).In this study,a split-plot design was used.Three grass species( Cynodon dactylon , Capillipedium assimile and Paspalum distichum )and four treatments(submerged at depths of 0,5,15 and 25 m)were arranged as the main-plot and sub-plot,respectively.The indices of recovery growth ability and photosynthetic characteristics of each treatment were examined,including photosynthetic rate( Pn ),transpiration rate( Tr ),stomatal conductance( Gs ),water use efficiency( WUE )and apparent CO 2 use efficiency( CUEapp ).The important findings were as follows:(1) Cynodon dactylon had the highest survival rate,and its survival rate was 100% in all of the three submerged depths.However,the survival rates of Capillipedium assimile and Paspalum distichum decreased with the increase in submerged depth,and their survival rates were 100% at the submerged depth of 5 m and more than 80% at the submerged depths of 15 m and 25 m.(2)Compared with the unsubmerged control group,each grass specie showed no significant differences in the indices of net photosynthetic rate( Pn ),transpiration rate( Tr ),stomatal conductance( Gs ),water use efficiency( WUE )and apparent CO 2 use efficiency( CUEapp )among the three submerged depths.Howerer, Pn , WUE and CUEapp of Cynodon dactylon were much higher than those of Capillipedium assimile and Paspalum distichum when compared with the treatments at the same submergence depth among the three grass species.(3)According to the recovery growth abilities and photosynthesis of three grass species,which were subjected to different stress of submerged depth,they could endure the stress of long-time and deep submergence.Based on the comprehensive consideration on vegetation restoration in the Three Gorges Reservoir Area,the three grass species are suitable for revegetation of water-level-fluctuation zone in the Three Gorges Reservoir Area.The order of endurance of long-time and deep submergence of the three grass species is as the following: Cynodon dactylon > Capillipedium assimile > Paspalum distichum .

硬秆子草( Capillipedium assimile )、双穗雀稗( Paspalum distichum )和狗牙根( Cynodon dactylon )在经受与三峡水库水位运行节律基本一致的水淹时间和水淹持续时期,但淹水深度(0、5、15和25m)不同的处理后,对其进行了恢复生长和光合特性研究。结果表明:(1)3种草本植物之间相比,狗牙根的存活率最高,所有处理植株存活率达到了100%;硬秆子草和双穗雀稗随着水淹深度的增加,存活率呈降低趋势,5m深处理存活率达到了100%,15m和25m深处理存活率在80%以上。(2)3种草本植物恢复生长后的叶片净光合速率 Pn 、蒸腾速率 Tr 、气孔导度 Gs 、水分利用效率 WUE 和表观CO 2 利用效率 CUEapp 与未淹对照相比没有显著差异;不同物种相同水淹处理之间比较,狗牙根的各光合指标显著高于硬秆子草和双穗雀稗。(3)结合三峡库区消落带植被恢复物种筛选的基本条件和本试验不同处理植株的恢复生长及其光合特性的研究,结果表明,硬秆子草、双穗雀稗和狗牙根是能够忍耐长期深淹胁迫的、适宜于三峡库区消落带植被恢复与重建的优良物种。三者之间的耐淹能力从大到小依次为:狗牙根>硬秆子草>双穗雀稗。

为了阐明水淹对三峡库区岸生植物野古草光合作用的影响,模拟了三峡库区消落带水淹发生情况,考察了在不同水淹处理下野古草(Arundinella anomala Steud.)的光合及叶绿素荧光特性.实验设置了对照 (不进行水淹,常规供水管理)、半淹 (植株置于水中,植株地上部分一半被淹没)、水下0.5m (植株置于水中,植株顶部在水面下0.5m)、水下2m (植株置于水中,植株顶部在水面下2m) 4个不同的水淹深度和0、20、40d和60d等 4个不同的水淹时间处理,测定了在不同水淹深度和水淹时间处理下野古草的净光合速率、总叶绿素含量、PSⅡ的最大光化学效率、电子传递速率、表观量子效率、叶绿素利用效率与羧化效率.结果发现,在水淹前期,水淹对野古草的光合特性影响较小,直到水淹60d后,才对野古草的光合特性产生明显影响,且影响程度随水淹深度的不同而不同.野古草在水淹20d和水淹40d后,各水淹处理的净光合速率与对照相比无明显降低,其中水淹20d后,半淹处理的野古草叶片净光合速率比对照还高出16.1%.水淹60d后,水下0.5m和水下2m的净光合速率显著低于对照和半淹,其净光合速率分别为7.51μmol·m-2·s-1和9.15μmol·m-2·s-1.结果表明,水淹20d和40d对野古草的电子传递速率、表观量子效率和羧化效率没有影响.水淹处理60d后,与对照植株相比,半淹处理植株的电子传递速率、表观量子效率、叶绿素利用效率和羧化效率没有明显变化,但水下0.5m和水下2m处理植株的电子传递速率、表观量子效率、叶绿素利用效率和羧化效率有明显降低. 在整个实验期间,半淹处理植株的净光合速率、电子传递速率、表观量子效率和羧化效率没有受到任何不利影响.尽管在水淹60d后水下0.5m和水下2m处理植株的净光合速率、电子传递速率、表观量子效率、叶绿素利用效率和羧化效率降低,但降低后的数值仍不低于甚至高于一些自然生长的未受水淹的植物物种.研究表明,野古草对水淹具有很好的耐受能力,是一种可以用于三峡库区消落区植被构建的优良植物物种.

Four flooding treatments (control, CK; continuous flooding, CF; periodic flooding, PF; and Full flooding, FF) were set in simulating the soil flooding change of the riparian zone in the Three Gorges Reservoir region of China to study the physiological and ecological adaptation mechanisms of two-year-old perennial Distylium chinense seedlings to the soil flooding change. There were no significant differences in height and basal diameter of the seedlings grown under different water regimes, while the content of chlorophyll, photosynthesis and fluorescence characteristics under different flooding forms were significantly different. Chlorophyll content, net photosynthetic rate( P n ), stomatal conductance( G s ), transpiration rate( Tr ), maximal photochemical efficiency ( F v /F m ), photochemical quenching ( q P ) and electron transfer rate (ETR) in CF and PF decreased significantly, and the decrease in PF was smaller than CF. In addition to chlorophyll content, G s and Tr , the other indicators were significantly different; Chlorophyll content, P n , G s , Tr , F v /F m , q P and ETR in FF were not significantly different compared with CK;Non-photochemical quenching( q N )in CF and PF was not significantly different from CK, while the q N in FF was decreased significantly. Although the chlorophyll content, P n , G s , Tr , F v /F m , q P and ETR in CF decreased significantly compared with the other treatments, the plants were able to form adventitious roots, hypertrophic lenticels and reduce the leaf increment to enhance resilience to flooding. Thus, D. chinense has strong tolerant capabilities to submergence, and shows a certain adaptability and plasticity in different flooding forms.

通过设置对照(CK)、持续性水淹(CF)、间歇性水淹(PF)和全淹(FF)4个水淹处理,模拟三峡库区秋冬季消落带土壤水淹变化,研究2年生中华蚊母树的生理生态适应机制。结果表明: 不同水淹形式并没有显著影响中华蚊母树的株高和基径,而光合色素含量、光合及叶绿素荧光特性在不同水淹形式下却有所差异,CF和PF植株光合色素含量、净光合速率( P n )、气孔导度( G s )、蒸腾速率( Tr )、最大光化学效率( F v / F m )、光化学猝灭( q P )以及电子传递速率(ETR)均出现了显著下降,但PF植株下降的幅度要小于CF植株,除光合色素含量、 G s 和 Tr 外,其他指标均差异显著,而FF植株光合色素含量、 P n 、 G s 、 Tr 、 F v / F m 、 q P 以及ETR均未受到水淹的影响,与CK植株差异不显著； CF和PF植株叶片非光化学淬灭( q N )未受到水淹的影响,但FF植株叶片 q N 与CK相比却显著下降。虽然CF植株较其他处理植株叶绿素含量、 P n 、 G s 、 Tr、F v / F m q P 以及ETR均下降明显,但水淹处理植株能够通过形成不定根、特化的皮孔以及减少叶片数量来增加耐淹能力。因此,中华蚊母树具有较强的耐淹能力,在不同水淹形式下均表现出一定的适应性和可塑性。

为合理利用三峡库区消落带优良草本植物进行退化植被恢复,并探索恢复过程中草本植物的最佳混植比例,选取三峡库区消落带适生先锋草本植物牛鞭草(Hemarthria compressa)(H)和狗牙根(Cynodon dactylon)(C)为研究材料,于2016年4月29日在盆栽控制条件下设置3种不同水分条件(对照组——CK组、浅淹组——SF组、全淹组——TF组)、7种配置比例,每盆牛鞭草与狗牙根株数分别按2株进行递增与递减,具体的配比分别为H0C12,H2C10,H4C8,H6C6,H8C4,H10C2、H12C0,比较研究混植条件下牛鞭草与狗牙根在水淹环境中的生长及二者的竞争作用。研究发现:(1)无论在单植还是二者混植条件下,水分胁迫均显著降低狗牙根与牛鞭草生物量,且牛鞭草对水淹胁迫的响应更敏感;(2)狗牙根和牛鞭草的生长均具有明显的密度制约效应,但狗牙根的反应更为强烈;(3)不同水分与密度条件下,混植体系总相对生物量均大于1。在CK组,狗牙根与牛鞭草表现出竞争关系;在SF组和TF组,二者之间的竞争作用减小,表现出一定的促进作用。综合分析本试验不同水分与密度条件下牛鞭草与狗牙根的总生物量、根冠比、竞争系数(相对总生物量),发现常规供水处理下牛鞭草和狗牙根的最佳配置比例为H2C10,而浅水淹和深水淹处理下最佳配置比例为H8C4。研究结果可以为三峡库区消落带不同海拔位草本植被的恢复及管理提供依据,也为生态类型相同或相似地区人工恢复草本植被提供理论参考。

研究了干旱胁迫对黄栌幼苗的相对含水量、膜透性、叶绿素含量、根系活力以及蒸腾和光合速率等几个生理指标的影响.结果表明;干旱胁迫对黄栌幼苗的几个生理指标影响显著;随着干旱胁迫程度的加剧和时间的延长,黄栌的叶绿素含量稳定上升;膜透性在整个干旱胁迫期间变化平稳,有下降趋势;蒸腾速率日变化均为先升后降的趋势;在干旱胁迫条件下,净光合速率、根系活力和相对含水量均呈下降趋势,但能持续维持在较高水平.黄栌具有抗旱性,叶绿素含量和膜透性能作为黄栌抗旱性评价的生理指标.

水蓼(Polygonum hydropiper)是一种分布于三峡地区消落带的常见物种.通过模拟4-5月的水淹节律,研究了水蓼对水淹的生理生态学响应机理.结果表明,各处理所有的植株存活率都保持100%.水淹改变了水蓼的日光合作用和日蒸腾作用节律,在水淹条件下的植株一天中能比对照更长时间地保持高水平的光合速率,短期水淹下植株的蒸腾速率呈"双峰"曲线,而对照和长期水淹下的植株则呈"单峰"曲线.植株在水淹条件下生长其光合速率和蒸腾速率都显著高于对照,但是随着水淹时间的延长这种增加效应会有所下降.植株叶片光合色素含量在水淹条件下也会发生显著变化,短期水淹使得光合色素含量增加,但随着水淹时间的延长,光合色素含量逐渐降低,长期水淹条件下,色素含量低于对照,由于植株能形成大量不定根,长期水淹对植株的生理活动并没有显著的负面影响.因此水蓼是一种比较耐淹的一年生草本植物,模拟水淹不仅没有影响到植株生长发育,在一定程度上还促进了植株的生理活动.文章最后结合三峡库区消落带未来生态环境的变化分析了该物种分布状况的变化趋势及其在消落带生态治理中的应用潜力.

在黄土半干旱区,采用人工控制土壤水分的方法,使用Li-6400便携式光合作用测定系统,对侧柏苗木净光合速率、蒸腾速率、气孔导度、胞间CO2浓度及其相应的环境因子进行了测定.结果表明:不同土壤水分状况下侧柏苗木光合速率日变化曲线呈"双峰"型,均有不同程度的 "午休"现象,且上午的光合速率明显高于下午;气孔导度受水分和光热胁迫的影响,日变化曲线呈凹型;胞间CO2浓度受空气CO2浓度和气孔导度的双重影响,呈现出早晚高,正午低的日变化进程;水分利用效最高值出现在上午较早的时分,且上午的水分利用效率明显高于下午;随着土壤水分的增加,净光合速率和蒸腾速率升高,而水分利用效率降低.根据Farquhar和Sharkey的观点,造成净光合速率下降的原因既有气孔限制又有非气孔限制因素,上午净光合速率下降的主要是由气孔限制因素造成的,午间和下午光合速率的降低则主要归因于叶肉细胞羧化效率的降低.

This paper mainly discussed the differences of cotton canopy structural characteristics and Photosynthetic quality in different density condition of the extend breed Xinluzao10 and Xinluzao12 in North Xinjiang cotton growing region,then discovered that high-density of theoretic plants 225 000 plants/hm 2 is the more sensible plant density.The experiment results indicated that both exorbitant density and too lower density of colony density are all not avail to forming ideal canopy structure and taking high yield.By the comparison between the two varieties,Xinluzao10 is more sensitive to high density and can acquire higher yield.Thus Xinluzao10 is better at high density condition and Xinluzao12 is better at mid-high density condition.Reduce LAI and canopy light interception,then increase canopy mean foliage inclination angle and transmission coefficient for diffuse penetration,transmission coefficient for radiation penetration.Then acquired the response of varieties toward different density and the ideal reasonable index of cotton canopy structure,and come to theoretical ground of increasing cotton production.

研究了北疆棉区推广棉种新陆早10号与新陆早12号在不同种植密度条件下冠层结构特征和光合特性的差异,得出高密度植棉理论密度225000株/hm 2 是较为适宜的种植密度。研究结果显示,群体密度过高或过低都不利于形成理想群体冠层和获得高产。2品种相比,新陆早10号较新陆早12号对高密度反应敏感,高密种植可获得较高产量。因此在高密条件下选择新陆早10号,中高密条件下选择新陆早12号栽培种植较为适宜。叶面积指数升高,叶片平均倾斜角度减小,群体散射辐射透过系数和群体直射辐射透过系数降低,对光能的截获率增加,由此得出了不同品种对种植密度的反应表现及理想群体冠层结构的合理指标,为增加棉花产量提供了理论依据。

Using wheat hybrid C6-38/Py85-1 and its parents (female C6-38 and male Py85-1) as materials, the effects and physiological mechanism of different planting densities on photosynthesis of flag leaf and grain yield were analyzed. At different density levels including low (L, 150 plants/m2), middle (M,

通过两个生长季(2006～2007年)的大田试验,研究了1:3和2:3两种问作模式及单作种植对玉米和大豆群体辐射截获与利用以及产量的影响.结果表明,单作玉米、单作大豆、1:3间作和2:3间作的消光系数分别为0.45、0.60、0.53和0.52.播后第79 d前,间作和单作玉米的干物质量间差异不显著;此后,1:3同作玉米的干物质量极显著高于单作玉米,1:3和2:3间作模式之间玉米干物质量的差异显著;观测期内,大豆干物质量单作和问作间差异显著.玉米/大豆1:3间作群体的辐射利用率(3.51 g·MS-1)和2:3间作群体的辐射利用率(3.49g·MJ-1)约为单作大豆辐射利用率(1.24g·MJ-1)的2.8倍.但略低于单作玉米(3.56g·MJ-).虽然单作玉米和大豆的籽粒产量均高于间作群体内玉米和大豆的籽粒产量,但间作群体的总产量分别比单作玉米和大豆的产量高约6.0%和320%;间作种植收入比单作玉米高56%～60%.比单作大豆高70%～74%.本研究表明,间作种植能够通过更有效地利用光能来增加作物产量,进而提高农民收入.

Cotton (Gossypium hirsutum) is an important crop in the Xinjiang Province in Northwest China, and high yields of high quality cotton can be produced under irrigation in the arid, continental climate of this region. In order to increase cotton yields in Xinjiang, we studied the effects of planting density (three treatments: 60 000 plants·hm-2, 180 000 plants·hm-2 and 300 000 plants·hm-2) on canopy photosynthetic rate, canopy structure and yield formation in two cotton varieties, `Xinluzao 6' and `Xinluzao 7'. Our results showed that canopy photosynthetic rates increased with planting density before full boll stage. Canopy photosynthetic rates of `Xinluzao 6' and `Xinluzao 7' at a planting density of 300 000 plants·hm-2 were 29.58 μmol CO2·m-2·s-1 and 26.16 μmol CO2·m-2·s-1 respectively, which was 10.4% and 6.5% higher than that of the medium density treatment of 180 000 plant·hm-2. In later growth periods after full boll stage, the canopy photosynthetic rate was maintained at a relatively high level in the medium density treatment, remained low in the low density treatment, but decreased rapidly in the high density treatment due to the decline of the leaf area index (LAI). LAI increased with planting density before full boll stage and attained maximum LAI at full boll stage. Generally, the canopy photosynthetic rate at each growth stage was significantly correlated with LAI (R=0.935*-0.998*, n=5) except for the `Xinluzao 6' in later full boll stage. The mean foliage angle of inclination, an important index for describing canopy structure, increased with planting density, whereas two other indices of canopy structure, the canopy transmission coefficient for radiation penetration and canopy transmission coefficient for diffuse penetration, decreased with planting density.Very high planting densities negatively impacted the canopy structure, resulting in a rapid decline of canopy photosynthetic rate. The accumulation of colonial photosynthetic product increased with an increase in planting density during the growth period. In the high density treatment, colonial photosynthetic product accumulation of `Xinluzao 6' and `Xinluzao 7' was 13 700 kg·hm-2 and 13 153 kg·hm-2, respectively, which was 1.5% and 2.0% higher than that of the medium density treatment, and 34.3% and 54.6% higher than that of the low density treatment. The allocation of photosynthetic product to flower buds and bolls was enhanced from full flower stage to later full boll stage in the medium and high density treatments. Total boll number per unit area increased with planting density. Weight per boll in the medium density planting was 5.61 g and 5.48 g in the two varieties, which was 2.6% and 11.5% heavier than in the high density treatment for the two varieties and 8.7% and 13.5% heavier than in the low density treatments. The canopy photosynthetic rate at full flower stage and boll opening stage were significantly correlated with lint yield. Therefore, the enhancement of the canopy photosynthetic rates during the full boll and opening boll stage could lead to increased of yields of lint.

在新疆气候生态条件下，研究了种植密度对棉花（Gossypium hirsutum）群体光合作用、冠层结构和产量形成的影响，探讨了新疆棉花高产的生理机理及进一步提高产量的途径。结果表明：群体光合速率在盛铃期以前随密度增加明显增强，盛铃期以后，低密度6万株·hm-2的群体光合速率仍为最低，高密度30万株·hm-2群体光合速率迅速下降，中密度18万株·hm-2则保持较高水平。叶面积指数的变化与群体光合速率的变化相似，其峰值出现在盛铃期。冠层结构各指标的变化表现为，随密度增加平均叶簇倾角变大，株型变紧凑，但密度过大，群体散射辐射与直射辐射透过系数小，冠层结构不良，造成生育后期群体光合速率较快下降。增加密度能增加单位面积总铃数，但密度过高削弱了棉株个体发育，生育后期群体光合速率下降早，造成单铃重降低。群体总光合物质累积与群体光合速率在各生育时期呈显著正相关，籽棉产量与群体光合速率仅在盛铃期和吐絮期呈显著正相关；生产上要实现棉花高产及超高产，应使棉花生育前期群体光合速率稳定上升，至盛铃期达到高峰值，吐絮期群体光合速率保持较高水平