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1.
春小麦拔节期有限供水的产量和生理效应研究初报   总被引:2,自引:0,他引:2  
本文研究了春小麦在中度水分亏缺(40%土壤毛管持水量,CW)生长下,拔节期不同水平供水处理(30─100%CW,10天)下的植株生长发育、水分代谢及产量组成方面的变化,初步发现,拔节期保持40%CW是水分利用的效率(WUE)与产量同步增加的下限,60%CW是达到较高WUE和较高产量的下限;春小麦拔节期增加限量供水能有效增加籽粒产量。产量增加又同植株干物质积累、株高、根系生长、旗叶面积及单株穗粒数紧密正相关。此外,拔节期有限供水的增加,蒸腾速度、叶水势和渗透势等生理指标也有一定程度的效应变化。  相似文献   

2.
氮对苹果幼树水分利用效率的影响   总被引:7,自引:0,他引:7  
以2年生盆栽新红星/平邑甜茶苹果树为试材,初步探讨了土壤不同水分状况下氮肥对植株水分利用效率(WUE)及有关参数的影响,结果表明,充足供水时,随施N量的增加,植株WUE降低,施N导致气孔导率(Gs)增大,对蒸腾(Tr)的提高幅度大于光合(Pn);供水不足时,施N植株的WUE明显高于对照,不同施N水平的WUE表现为:高N〉中N〉低N,WUE改善是由于叶肉羧化能力提高,导致光合增强。  相似文献   

3.
冬小麦对有限水分高效利用的生理机制   总被引:18,自引:3,他引:15  
通过对不同土壤供水条件下的孕穗开花期的冬小麦叶片CO2/ H2O 气体交换参数的系统测定,研究了光合速率(Pn) 、蒸腾速率( Tr) 、气孔导度( Gs) 、细胞间隙CO2 浓度(Ci) 、叶温( Tl) 与水分利用效率( WUE) 间的关系.结果表明,WUE 并不随Pn 的增长直线增长,而是呈现出二次曲线的变化趋势;只有当蒸腾达到一定程度时,Tr 才对WUE 产生影响,而Tr 过大时W UE 则有下降的趋势;WUE 与Ci 呈负相关,随Ci 的增加WUE 呈递减趋势;叶温升高对光合和蒸腾都有促进作用,当超过了某种限度则表现为抑制作用,表明在一定温度范围内,Tl 升高对水分利用不利;随Gs 的增大,WUE 增大到一定程度则不再增加,甚至出现一种回落趋势  相似文献   

4.
干旱胁迫对水稻水分利用效率的影响   总被引:5,自引:0,他引:5  
通过特殊自然干旱胁迫的方法,研究不同干旱胁迫对水稻的水分利用效率(WUE)的影响,在一定供水量时,水稻的WUE随供水量的增加而下降,但水稻旱种时,却因供水量过低,干旱胁迫严重,WUE值为最低。不同品种的水稻WUE存在较大的差异,抗旱性强的品种具有较高WUE,因此选用具有较高WUE的品种,是水稻节水栽培的关键。  相似文献   

5.
谷子叶片光合速率日变化及水分利用效率   总被引:2,自引:0,他引:2  
通过降低空气湿度( 从约30 % 减少到5 % ) 、增加CO2 浓度( 从400 μl CO2/L增加到730 μl CO2/L) 、烫叶鞘破坏韧皮部等处理对谷子叶片光合速率日变化和水分利用效率(WUE) 进行了研究, 发现中午光合速率降低与光合产物积累有关; 虽然低大气相对湿度(5 % ) 使光合速率有所降低,但提高了WUE。而烫叶鞘使光合物质积累既抑制了光合速率,又降低了WUE。  相似文献   

6.
谷子叶片光合速率日变化及水分利用效率   总被引:51,自引:0,他引:51  
通过降低空气湿度(从约30%减少到5%)、增加CO2浓度(从400μlCO2/L啬到730μlCO2/L)、烫叶鞘破坏韧皮部等处理对谷子叶片光合速率日变化和水分利用效率(WUE)进行了研究,发现中午光合速率降低与不合冰物积累有关;虽然低大所相对湿度(5%)使光合速率有所降低,但提高WUE。而烫叶鞘使光合物质积累既抑制了光合速率,又降低了WUE。  相似文献   

7.
有限供水对复玉米产量及其水分利用效率的影响   总被引:9,自引:0,他引:9  
在人工控制水分的测试坑条件下,对玉米全生育期的研究表明;随供水量减少则根系耗水深度明显加深,土壤各层次含水量变化较大。当供水量从适宜供水下降到中度亏缺供水时,则耗水深度由80cm增加到120cm;在各生育期蒸腾速率,光合速率及产量和水分利用效率均随供水量的下降而下降;研究单叶水分利用效率表明:顶层第二叶在各叶层中最高;其日变化是9:00-11:00时单叶WUE最高。  相似文献   

8.
有限供水对夏玉米产量及其水分利用效率的影响   总被引:16,自引:1,他引:15  
在人工控制水分的测试坑条件下,对玉米全生育期的研究表明;随供水量减少则根系耗水深度明显加深,土壤各层次含水量变化较大。当供水量从适宜供水下降到中度亏缺供水时,则耗水深度由80cm增加到120cm;在各生育期蒸腾速率,光合速率及产量和水分利用效率均随供水量的下降而下降;研究单叶水分利用效率表明:顶层第二叶在各叶层中最高;其日变化是9:00-11:00时单叶WUE最高。  相似文献   

9.
控制小麦种、属旗叶水分利用效率的染色体背景分析   总被引:27,自引:0,他引:27  
张正斌  山仑  徐旗 《遗传学报》2000,27(3):240-246
利用LCA-3便携式光合仪对不同染色体背景的材料测定表明,就旗叶水分利用效率(WUE)而言,不同染色体组的上排序为AA>BB>DD>RR,说明A组染色体上载有控制高WUE的基因,对中国春双端体系列的研究表明,A组染色体无论在缺失长臂和短臂时,其端体也保持较高的旗叶WUE,在1AL、2AL、2AS、7AS染色体臂上载有控制高WUE的基因。对小黑麦附加系的研究表明,4R染色体上载有控制高WUE的基因,  相似文献   

10.
水分胁迫和氮素营养对小麦根苗生长及水分利用效率的效应   总被引:33,自引:3,他引:30  
采用目前生产上广泛种植的小麦品种小偃6号,在一种特制木盒中土培,研究了水分胁迫和氮素营养对小麦根系和幼苗生长及水分利用效率(WUE)的效应。小麦根系生长在双层尼龙网之间,土壤中的水分和养分可以被正常吸收,但主根和侧根不能穿过。结果表明:在土壤含水量为田间持水量的40%-70%范围内,随着土壤干旱程度的增加,小麦根长(RL)、根干重(RDW)、叶面积(LA)和WUE显著降低。氮肥的效应更为复杂。随着  相似文献   

11.
干旱与复水对小麦光合和产量的影响   总被引:8,自引:2,他引:6  
通过不同生育期变水处理,研究干旱胁迫和复水处理分别对不同基因型小麦光合和产量影响。结果表明:拔节期为亏缺敏感期,该期胁迫引起产量显著降低,相比充分供水处理普通小麦减产25.93%,同时光合速率、水分利用效率、收获指数均下降,蒸腾增强;灌浆期为复水高效期,对比胁迫处理普通小麦增产38.78%,光合增强,水分利用效率和收获指数增加,蒸腾减弱。  相似文献   

12.
采用自动式遮雨棚水分精量控制试验研究了交替地下滴灌条件下不同灌溉定额对春玉米产量和水分利用效率的影响.结果表明:交替地下滴灌春玉米需水关键时期为拔节-抽雄期、抽雄-灌浆期,具体表现为耗水模系数与耗水强度大,且对水分敏感性高,在灌溉条件有限的情况下要优先满足春玉米这两个时期的水分需求.随着灌溉定额的增加,产量呈现增加趋势;灌溉定额小于2764.5 m3·hm-2时产量随灌溉定额增加快速增加,大于2764.5 m3·hm-2时产量随灌溉定额增加缓慢增加;当灌溉定额为3357.1 m3·hm-2时产量最高,达12109.0 kg·hm-2.与固定地下滴灌相比,在灌溉定额相同条件下,交替地下滴灌产量提高5.4%,水分利用效率提高1.4%,灌溉水利用效率提高5.6%.与固定地下滴灌相比,灌溉定额减少20%时,交替地下滴灌虽然产量下降1.8%,但水分利用效率提高11.0%,灌溉水利用效率提高22.7%.综合考虑产量、水分利用效率两个指标,确定试验区春玉米交替地下滴灌的适宜灌溉定额为1600.4~3357.1 m3·hm-2.  相似文献   

13.
用化肥减量和分期施肥、增施有机肥来替代化肥是提高半干旱区全膜覆盖垄沟种植马铃薯水、肥利用效率的有效途径.在4年大田定位试验基础上,设置传统施肥(F)、化肥减量25%花期追施(DF)、化肥减量50%花期追施并增施有机肥(OF)3种养分管理模式,通过测定马铃薯不同生育期的土壤含水量和产量,计算阶段耗水量和水分利用效率,研究施肥方式对半干旱区马铃薯耗水过程的调控及其对产量和水分利用效率的影响.结果表明: 马铃薯花期的土壤贮水量DF最高,但处理间差异不显著;花后DF和OF的耗水深度较F有明显增加趋势.与F相比,2011—2014年DF花前耗水量显著下降,花后耗水量分别增加了36.2%、23.0%、24.8%和19.0%;OF未显著降低马铃薯花前耗水,但2011、2012年花后耗水量增加了20.7%和16.3%.DF的马铃薯块茎产量在2012—2014年较F平均增加2595.1 kg·hm-2,水分利用效率(WUE)在2013、2014年分别显著增加14.4%和6.3%,达到显著差异;OF在2011—2014年平均马铃薯块茎产量较F增加了2945 kg·hm-2,且WUE在2012—2014年显著高于F.DF和OF均能显著调节马铃薯花前花后耗水量,使马铃薯块茎产量、水分利用效率增加,但OF的增加幅度更大.  相似文献   

14.
科学灌溉对植物种子生产具有重要意义。本研究以荒漠草原优良乡土植物沙芦草和牛枝子为对象,以充分灌溉为对照,探究不同生育时期亏缺灌溉对两种牧草种子生产和水分利用效率的影响。结果表明: 与对照相比,亏缺灌溉下两种植物土壤含水率下降,其中沙芦草土壤含水率下降主要发生在0~60 cm土层,牛枝子土壤水分下降未出现明显的分层现象。亏缺灌溉下沙芦草种子产量各构成因子差异均显著,开花期亏缺灌溉种子产量最高;牛枝子仅生殖枝数、小花数和荚果数差异显著,种子产量各处理差异不显著。相关分析显示,沙芦草种子产量与生殖枝数(r=0.776)、小穗数(r=0.717)呈显著正相关;牛枝子花序数与生殖枝数呈极显著负相关(r=-0.685),与小花数呈显著正相关(r=0.412)。与充分灌溉相比,亏缺灌溉下两种乡土植物种子生产耗水量减少,水分利用效率提高,其中,沙芦草开花期亏缺灌溉水分利用效率提高最多(32.9%);牛枝子分枝期亏缺灌溉提高最多(27.4%)。因此,适当亏缺灌溉可以提高两种植物水分利用效率。从水分利用效率和种子产量来看,干旱区沙芦草和牛枝子种子人工繁育时可采取亏缺灌溉,适宜亏缺的生育期分别为开花期和分枝期。  相似文献   

15.
Deficit irrigation in winter wheat has been practiced in the areas with limited irrigation water resources. The objectives of this study were to (i) understand the physiological basis for determinations of grain yield and water-use efficiency in grain yield (WUE) under deficit irrigation; and (ii) investigate the effect of deficit irrigation on dry matter accumulation and remobilization of pre-anthesis carbon reserves during grain filling. A field experiment was conducted in the Southern High Plains of the USA and winter wheat (cv. TAM 202) was grown on Pullman clay loam soil (fine mixed thermic Torretic Paleustoll). Treatments consisted of rain-fed, deficit irrigation from jointing to the middle of grain filling, and full irrigation. The physiological measurements included leaf water potential, net photosynthetic rate (Pn), stomatal conductance (Gs), and leaf area index. The rain-fed treatment had the lowest seasonal evapotranspiration (ET), biomass, grain yield, harvest index (HI) and WUE as a result of moderate to severe water stress from jointing to grain filling. Irrigation application increased seasonal ET, and ET increased as irrigation frequency increased. The seasonal ET increased 20% in one-irrigation treatments between jointing and anthesis, 32-46% in two-irrigation treatments, and 67% in three- and full irrigation treatments. Plant biomass, grain yield, HI and WUE increased as the result of increased ET. The increased yield under irrigation was mainly contributed by the increased number of spikes, and seeds per square meter and per spike. Among the irrigation treatments, grain yield increased significantly but the WUE increased slightly as irrigation frequency increased. The increased WUE under deficit irrigation was contributed by increased HI. Water stress during grain filling reduced Pn and Gs, and accelerated leaf senescence. However, the water stress during grain filling induced remobilization of pre-anthesis carbon reserves to grains, and the remobilization of pre-anthesis carbon reserves significantly contributed to the increased grain yield and HI. The results of this study showed that deficit irrigation between jointing and anthesis significantly increased wheat yield and WUE through increasing both current photosynthesis and the remobilization of pre-anthesis carbon reserves.  相似文献   

16.
Soil water deficit is a major limitation to agricultural productivity in arid regions. Leaf photosynthesis can quickly recover after rewatering and remains at a higher level for a longer period, thus increasing crop yield and water-use efficiency (WUE). We tested our hypothesis that leaf photosynthesis and root activity of water-stressed cotton (Gossypium hirsutum L.) plants could quickly recover after rewatering at a certain growth stage and it should not influence a cotton yield but increase WUE. Treatments in this study included two degrees of water stress: mild water stress (V1) and moderate water stress (V2) imposed at one of four cotton growth stages [i.e., S1 (from the full budding to early flowering stage), S2 (from early flowering to full flowering), S3 (from full flowering to full bolling), and S4 (from full bolling to boll-opening)]. The soil water content before and after the water stress was the same as that in the control treatment (CK, 70–75% of field capacity). Water deficit significantly reduced the leaf water potential, net photosynthetic rate, and stomatal conductance in cotton. The extent of the decline was greater in S2V2 treatment compared to others. Water deficit also reduced root activity, but the extent of inhibition varied in dependence on soil depth and duration. When plants were subjected to S1V1, the root activity in the 20–100 cm depth recovered rapidly and even exceeded CK one day after rewatering. An overcompensation response was observed for both photosynthesis and aboveground dry mass within one to three days after rewatering. Compared with the CK, S1V1 showed no significant effect on the yield but it increased total WUE and irrigation WUE. These results suggest that even a short-term water stress during the S1, S2 and S4 stages mitigated, with respect to the root activity, the negative effect of drought and enhanced leaf photosynthesis compensatory effects of rewatering in order to increase cotton WUE with drip irrigation under mulch in arid areas.  相似文献   

17.
节水农业及其生理生态基础   总被引:189,自引:17,他引:172  
提高自然降水和灌溉水利用效率是节水农业要解决的中心问题。近年实践证明,通过提高水分利用率的途径增加农田生产力存在很大潜力,节水和增产的目标可能同时实现。为实现这一目标,需要研究确定植物水分亏缺的允许程度。植物各个生理过程对水分亏缺的敏感性不同,综合文献报道和作者研究结果,水分亏缺对与作物产量密切相关生理过程影响的先后顺序为:生长—蒸腾—光合—运输。在一定条件下,有限水分亏缺不会对作物最终经济产量造成影响,但却能显著提高水分利用效率。  相似文献   

18.
Water is an increasingly scarce resource worldwide and irrigated agriculture remains one of the largest and most inefficient users of this resource. Low water use efficiency (WUE) together with an increased competition for water resources with other sectors (e.g. tourism or industry) are forcing growers to adopt new irrigation and cultivation practices that use water more judiciously. In areas with dry and hot climates, drip irrigation and protected cultivation have improved WUE mainly by reducing runoff and evapotranspiration losses. However, complementary approaches are still needed to increase WUE in irrigated agriculture. Deficit irrigation strategies like regulated deficit irrigation or partial root drying have emerged as potential ways to increase water savings in agriculture by allowing crops to withstand mild water stress with no or only marginal decreases of yield and quality. Grapevine and several fruit tree crops seem to be well adapted to deficit irrigation, but other crops like vegetables tend not to cope so well due to losses in yield and quality. This paper aims at providing an overview of the physiological basis of deficit irrigation strategies and their potential for horticulture by describing the major consequences of their use to vegetative growth, yield and quality of different crops (fruits, vegetables and ornamentals).  相似文献   

19.
Water is an increasingly scarce resource worldwide and irrigated agriculture remains one of the largest and most inefficient users of this resource. Low water use efficiency (WUE) together with an increased competition for water resources with other sectors (e.g. tourism or industry) are forcing growers to adopt new irrigation and cultivation practices that use water more judiciously. In areas with dry and hot climates, drip irrigation and protected cultivation have improved WUE mainly by reducing runoff and evapotranspiration losses. However, complementary approaches are still needed to increase WUE in irrigated agriculture. Deficit irrigation strategies like regulated deficit irrigation or partial root drying have emerged as potential ways to increase water savings in agriculture by allowing crops to withstand mild water stress with no or only marginal decreases of yield and quality. Grapevine and several fruit tree crops seem to be well adapted to deficit irrigation,but other crops like vegetables tend not to cope so well due to losses in yield and quality. This paper aims at providing an overview of the physiological basis of deficit irrigation strategies and their potential for horticulture by describing the major consequences of their use to vegetative growth, yield and quality of different crops (fruits, vegetables and ornamentals).  相似文献   

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