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1.
在秋播花生开花下针期至饱果成熟期给予不同程度的干旱处理,结果表明,无论是轻度、中度或严重干旱均影响果实的发育,使代谢源中的同化物向代谢库(荚果)中输出减少,植株叶片的含水量下降,蒸腾速率、光合速率及叶绿素含量降低,呼吸速率升高,同时花生经济产量降低。  相似文献   

2.
Four potato varieties were subjected to water stress under controlled conditions. Leaf relative water content, leaf diffusive resistance, and photosynthesis were measured on stressed and unstressed plants during a stress period and during the recovery period following stress relief. Subsequent to the stress, plants were grown to maturity with optimal water supply. Mature plants were harvested and tuber yield and haulm production measured. Stressed plants of all varieties exhibited an increase in leaf diffusive resistance and a decrease in relative water content, transpiration, and photosynthesis as soil moisture decreased. Significant varietal differences in leaf diffusive resistance of stressed plants are apparent and offer promise for development of a screening technique for varietal sensitivity to drought based on stomatal response to water deficits.  相似文献   

3.
以中早熟品种“坝薯9号”、中晚熟品种“坝薯10号”和“乌盟851”为试材,研究了干旱对马铃薯的影响,结果表明:①随着水分胁迫时间的延长和胁迫强度的增加,叶片相对含水量和叶水势下降,蒸腾强度减弱,伤流量减少;植株高度、茎粗、叶片长和宽、功能叶间距均降低;块茎单株产量和收获指数降低,块茎干物质含量提高;叶绿素含量与光合作用强度随水分胁迫时间延长而降低,但随胁迫强度的增加而提高.②单株产量与叶水势和收获指数是显著正相关,与块茎干物质含量是显著负相关.③坝薯9号和乌盟851是两个耐旱品种.  相似文献   

4.
5.
A field experiment was conducted during 2001-2003 to evaluate the effect of water stress on the yield and yield components of four rice cultivars commonly grown in Mazandaran province, Iran. In northern Iran irrigated lowland rice usually experiences water deficit during the growing season include of land preparation time, planting, tillering stage, flowering and grain filing period. Recently drought affected 20 of 28 provinces in Iran; with the southeastern, central and eastern parts of the country being most severely affected. The local and improved cultivars used were Tarom, Khazar, Fajr and Nemat. The different water stress conditions were water stress during vegetative, flowering and grain filling stages and well watered was the control. Water stress at vegetative stage significantly reduced plant height of all cultivars. Water stress at flowering stage had a greater grain yield reduction than water stress at other times. The reduction of grain yield largely resulted from the reduction in fertile panicle and filled grain percentage. Water deficit during vegetative, flowering and grain filling stages reduced mean grain yield by 21, 50 and 21% on average in comparison to control respectively. The yield advantage of two semidwarf varieties, Fajr and Nemat, were not maintained under drought stress. Total biomass, harvest index, plant height, filled grain, unfilled grain and 1000 grain weight were reduced under water stress in all cultivars. Water stress at vegetative stage effectively reduced total biomass due to decrease of photosynthesis rate and dry matter accumulation.  相似文献   

6.
土壤干旱胁迫对白芥光合器官发育及光合速率的影响   总被引:5,自引:1,他引:5  
利用旱棚盆栽研究了在土壤干旱胁迫下白芥抗旱和不抗旱品系的单叶面积,单株叶面积、出叶速度、叶绿素含量和和净光合速率。结果表明,在土壤干旱胁迫下不同白品系在不同生育时期的单叶面积、单株叶面积、出叶速度及净光合速率都下降,在一定土壤水分范围内,叶绿素含量随土壤水分的下降而增加,抗旱性强的品系受土壤干旱胁迫的影响较小。  相似文献   

7.
Summary A lysimeter experiment was performed to study the optimal allocation of limited water supply in potatoes. Irrigation regimes equal to 40, 60 and 80% of maximum evapotranspiration (ET) were evenly applied over the crop cycle. Other treatments involved withholding 80 mm of irrigation, based on ET, beginning at each of three designated growth stages (tuber initiation, early and late tuber growth). An irrigated control treatment, restoring the entire ET, was included for comparison. Continuous drought stress reduced photosynthesis as irrigation volumes were reduced. Plant biomass and tuber yield decreased almost proportionally to water consumption, so that WUE was roughly constant. N uptake was highest in the control and in 80% ET treatment. Withholding water during tuberisation severely hindered plant physiological processes and penalized tuber yield. Reductions in photosynthesis, total biomass and yield were the greatest when drought was imposed during tuber initiation. The earliest stress resulted in the lowest WUE and N uptake. A new crop water stress index (SI) was proposed, which combines atmospheric demand for water and canopy temperature.  相似文献   

8.
DA-6对花生花期干旱胁迫下的生理效应   总被引:3,自引:0,他引:3  
选择花生需水量大的盛花期研究DA-6的生理效应.结果表明,干旱后喷施DA-6能提高叶片水分利用效率,降低离体叶片失水率,改善叶片的水分状况.干旱胁迫后膜脂过氧化产物丙二醛和有机渗透调节物质脯氨酸的含量均大幅度上升,DA-6的处理能降低这2种物质的含量,从而减缓干旱胁迫对花生造成的伤害.  相似文献   

9.
A field study was carried out from 1995 to 1997 in order to determine the effect of irrigation and water stress imposed at different development stages on vegetative growth, grain yield and other yield components of corn (Zea mays L.). The field trials were conducted on a silty loam Entisol soil, with Pioneer 3377 corn hybrid. A randomised complete block design with three replications was used. Four known growth stages of the plant were considered and a total of 16 (including rain fed) irrigation treatments were applied. The effect of irrigation or water stress at any stage of development on plant height, leaf area index, grain yield per hectare, as well number of ears per plant, grain yield per cob and 1000 kernels weight, were evaluated. Results of this 3-year study show that all vegetative and yield parameters were significantly affected by water shortage in the soil profile due to omitted irrigation during the sensitive tasselling and cob formation stages. Water stress occurring during vegetative and tasselling stages reduced plant height, as well as leaf area development. Short-duration water deficits during the rapid vegetative growth period caused 28–32% loss of final dry matter weight. Highest yields were observed in the fully irrigated control (VTCM) and the treatment which allowed water stress during the vegetative growth stage (TCM). Even a single irrigation omission during one of the sensitive growth stages, caused up to 40% grain yield losses during dry years such as 1996. Much greater losses of 66–93% could be expected as a result of prolonged water stress during tasselling and ear formation stages. Seasonal irrigation water amounts required for non-stressed production varied by year from 390 to 575 mm. Yield response factor (ky) values (unitless parameter) relating yield loss to water deficits) obtained for the first, second and third experimental years were determined to be 1.22, 1.36 and 0.81, respectively.  相似文献   

10.
甘薯植株形态、生长势和产量与品种抗旱性的关系   总被引:12,自引:0,他引:12  
对水分胁迫下甘薯(IpomoceabatatasLam.)植株形态、生长势和产量性状等指标与品种抗旱性关系的研究结果表明,水分胁迫下不同甘薯品种叶片厚度(包括栅栏组织、海绵组织的厚度及叶片总厚度)、藤叶和块根烘干率比对照均有所增加,叶片大小、叶面积指数(LAD、比叶面积SLA)、主蔓长、主蔓粗、节间长、藤叶和块根重量(鲜、干重)均不同程度减小。栅栏组织厚度、经济系数LAI、分枝数、块根干重及块根烘干率的相对值(占对照%)与品种抗旱性呈显著或极显著正相关(=0.5566~0.9352∶P<0.05,0.01),主蔓长、节间长及SLA的相对值与品种抗旱性呈显著或极显著负相关(r=-0.5289~-0.737;P<0.05,0.01),带有直立或缠绕性株型的比纯粹匍匐型品种的抗旱性强。  相似文献   

11.
《Field Crops Research》2002,73(2-3):181-200
A series of experiments were conducted in drought-prone northeast Thailand to examine the magnitude of yield responses of diverse genotypes to drought stress environments and to identify traits that may confer drought resistance to rainfed lowland rice. One hundred and twenty eight genotypes were grown under non-stress and four different types of drought stress conditions.Under severe drought conditions, the maintenance of PWP of genotypes played a significant role in determining final grain yield. Because of their smaller plant size (lower total dry matter at anthesis) genotypes that extracted less soil water during the early stages of the drought period, tended to maintain higher PWP and had a higher fertile panicle percentage, filled grain percentage and final grain yield than other genotypes. PWP was correlated with delay in flowering (r=−0.387) indicating that the latter could be used as a measure of water potential under stress. Genotypes with well-developed root systems extracted water too rapidly and experienced severe water stress at flowering. RPR which showed smaller coefficient of variation was more useful than root mass density in identifying genotypes with large root system.Under less severe and prolonged drought conditions, genotypes that could achieve higher plant dry matter at anthesis were desirable. They had less delay in flowering, higher grain yield and higher drought response index, indicating the importance of ability to grow during the prolonged stress period.Other shoot characters (osmotic potential, leaf temperature, leaf rolling, leaf death) had little effect on grain yield under different drought conditions. This was associated with a lack of genetic variation and difficulty in estimating trait values precisely.Under mild stress conditions (yield loss less than 50%), there was no significant relationship between the measured drought characters and grain yield. Under these mild drought conditions, yield is determined more by yield potential and phenotype than by drought resistant mechanisms per se.  相似文献   

12.
D. Levy 《Potato Research》1983,26(4):315-321
Summary The effect of repeated short periods of water stress during the hot season on six potato cultivars was investigated. The number of tubers per plant tended to decrease in response to water stress in cultivars which had more than 9.8 tubers per control plant (Désirée, Alpha, Elvira). In the other cultivars, no consistent effect of water stress on tuber number per plant was observed. Except for Spunta, the percentage of large tubers (>60 g/tuber) was reduced in the water-stressed plants. Consequently, the average weight of these tubers was greater than that of tubers harvested from the unstressed plants, indicating that the sink force of the individual tuber was not impaired by drought. However, tuber yield per plant was reduced due to drought in all cultivars tested. The smallest decrease in dry matter accumulation as well as the greatest lowering of the osmotic potential in the tuber tissue was found in Alpha. No consistent effect of water stress on the percentage of misshapen and sprouting tubers was observed, indicating the marked effect of the high temperature on these traits. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No 310-E, 1981 series. This investigation was sponsored by a grant from the Ministry for Development Cooperation of the Netherlands.  相似文献   

13.
Potato (Solanum tuberosum L.) is highly sensitive to soil drought and extracts less of the available water from the soil than other crops. Even a very short period of water shortage has a negative effect on consumptive and technological properties of potato tubers. The cause of the poorer properties of potato tubers might not only be water shortage itself but could also be the enhanced production of reactive oxygen species (ROS) accompanying practically every kind of stress, both biotic and abiotic. However, antioxidative enzymes seem to counteract the ROS accumulation and, thus, might protect plants against the deleterious effects of environmental stresses. Our research shows that increased activity of peroxidase, superoxide dismutase and catalase protects plants from oxidative stress, and, consequently, against yield losses.  相似文献   

14.
干旱胁迫对不同肥水类型小麦旗叶光合特性及产量的影响   总被引:8,自引:0,他引:8  
为给小麦抗旱育种和节水高产栽培提供理论和技术支持,在防雨旱棚池栽条件下研究了干旱胁迫对6个不同肥水类型小麦品种旗叶光合特性和产量的影响。结果表明,干旱胁迫条件下,小麦开花后旗叶的净光合速率、气孔导度、蒸腾速率、气孔限制值和单叶水分利用效率均呈下降趋势,而胞间CO2浓度有所升高。其中,水浇地品种烟农21、烟农24和济麦22净光合速率、气孔导度、蒸腾速率、气孔限制值和单叶水分利用效率较低且下降幅度大,而旱地品种青麦6号、济旱5034和鲁麦21的净光合速率、气孔导度、蒸腾速率、气孔限制值和单叶水分利用效率较高且下降较为缓慢,而胞间CO2浓度较低。青麦6号具有较高的抗旱指数,在干旱胁迫条件下能够保持较好的叶片结构和功能状况,是其获得高产的重要原因。  相似文献   

15.
为探明菠萝田间控水减肥效应及确定补充灌溉施肥水平,为粤西地区菠萝生产中节水节肥和提质增效提供依据。研究以金菠萝‘MD-2’为材料,设置无灌溉常规施肥(常规),2个补灌W1(-15~-35 kPa)和W2(-35~-55 kPa)与3个肥料F1(100%)、F2(75%)和F3(50%)梯度处理(F1W1、F2W1、F3W1、F1W2、F2W2、F3W2),以无灌溉无施肥作为对照(CK)。研究菠萝光合面积、光合效率、干物质积累、经济性状、灌溉水生产力及肥料偏生产力对不同处理的响应。结果表明,补充灌溉施肥能够显著提高菠萝株高、叶长、叶宽、叶片数和植株干物质含量。水肥限制下,叶片数和叶长的减少是单株叶面积下降的主要因素,而光合面积的减小是干物质量下降的主要因素,菠萝植株生长受限来自于肥料减施和因干旱而导致的肥料利用受限。雨季干旱胁迫解除后叶片实际光化学效率(ΦPSII)能够快速恢复,但营养生长期光合面积显著下降的不可逆转仍然导致果实干物质量和产量显著下降。补充灌溉施肥条件下肥料偏生产力表现为F3>F2>F1,而果实田间产量和田间糖锤度均表现为F32≈F1,因此确定F2是最佳施肥水平;在F2施肥水平下,水分生产力表现为W2>W1,但果实增产率和田间糖锤度在W1和W2之间差异不显著。因此,采用F2W2补充灌溉施肥方式可为菠萝生产中节水节肥和提质增效提供支撑。  相似文献   

16.
《Field Crops Research》1997,54(1):51-64
Various soybean cultivars were grown under different watering regimes in the field and greenhouse in south-eastern U.S.A. (1995 and 1996), and in the field in north-eastern Western Australia (1995). Aqueous glycinebetaine was applied at different growth stages onto their foliage with the objective of ameliorating effects of water stress on photosynthesis activity, nitrogen fixation, leaf growth, biomass accumulation and seed yield. There were cultivar differences in response to drought. Trends which suggest that exogenous glycinebetaine could improve photosynthesis activity, nitrogen fixation and leaf area development, were established. The observed seed yield increase of both well-watered and drought-stressed plants was associated with greater number of seeds following the application of 3 kg ha−1 glycinebetaine. The results indicate that foliar-applied glycinebetaine possesses anti-transpirant properties and has the potential to improve drought tolerance and reduce the amount of water used for irrigation, without any significant decrease in economic yield. There is evidence that soybean could be classified as a low-accumulator of glycinebetaine.  相似文献   

17.
《Field Crops Research》2005,91(2-3):149-160
Barley is one of the most widely cultivated crops in rainfed areas of the Mediterranean, where drought is the main factor that limits yield. Knowledge of the physiological traits responsible for adaptation of barley cultivars to Mediterranean environments may be relevant for future breeding strategies. Yield potential versus drought tolerance is an open debate. Here, we studied two barley cultivars (Graphic and Kym), of similar time to anthesis and crop duration, that are widely cultivated in the western Mediterranean. Grain yield was evaluated in 41 field trials and ranged (averaged for the 16–32 cultivars assayed in each trial) from 0.7 to 9.1 Mg ha−1. Yield components and carbon isotope discrimination (Δ13C) of grains was analysed in another two trials. Graphic production was greater than Kym in all conditions. This greater yield was sustained mainly by more ears per unit ground area, which may be attributable to higher growth potential during tillering. Moreover, Graphic showed greater Δ13C of kernels, indicating improved water status even at the end of the crop cycle. To examine differences in early growth, these cultivars were grown in optimal conditions and then photosynthetic activity and biomass analysed at the end of tillering. Graphic showed greater above-ground and root biomass as well as total leaf area per plant and per tiller than Kym, and also tended to have more tillers per plant, but its shoot-to-root biomass ratio was lower. Nitrogen content per unit leaf area was correlated negatively with plant and with tiller leaf area and positively with the shoot-to-root biomass ratio. Photosynthetic rate per unit leaf area was lower in Graphic and positively related to a lower nitrogen content, whereas stomatal limitation of photosynthesis and water use efficiency was similar in the two cultivars. Ribulose 1,5-biphosphate regeneration capacity contributed to the lower photosynthetic rate of Graphic. Moreover, quantum yield of photosystem II (PSII) electron transport was also lower in Graphic than Kym, which suggests that mechanisms other than leaf structure also contributed to the higher photosynthetic capacity of the former. Nevertheless, as result of differences in leaf area, total plant photosynthesis was greater in Graphic.The results indicate that the higher yield of Graphic under a wide range of Mediterranean conditions may be sustained by increased plant growth and total photosynthesis during tillering, although the photosynthetic capacity per unit leaf area is lower than that of Kym. Graphic has a more extensive root system than Kym, subsequently improving its water status in later stages of the crop cycle. Nitrogen content per unit leaf area is a good indicator of the growth and photosynthetic activity of barley plants in the early stages of the crop cycle.  相似文献   

18.
不同基因型玉米自交系的抗旱性研究与评价   总被引:17,自引:1,他引:17  
通过田间直接鉴定,采用模糊函数法,以抗旱隶属度、产量抗旱系数和抗旱指数为评价参数,分析各性状与参数间的关系,并运用主成分分析选择出有效的评价参数和指标,对各自交系进行抗旱性综合评价和聚类分析。结果表明,干旱导致玉米自交系的散粉至吐丝期间隔增加,光合叶面积减少,株高和穗位高降低,茎秆变细,穗短小,秃尖多,穗粒数少,粒重轻,最终导致产量下降。不同基因型间因抗旱性差异而所受影响明显不同,各自交系抗旱性强弱与干旱条件下的性状表现有较大关系,其中79-1E、交51、苏1-1和18599的抗旱性较好。各评价参数中,以产量抗旱指数和抗旱隶属度与干旱条件下各性状之间呈极显著或显著相关。抗旱指数、抗旱隶属度、产量和叶面积是抗旱性综合评价最有效的参数和指标。  相似文献   

19.
Gas-exchange characteristics of potato (Solanum tuberosum L.) canopies were determined with crop enclosures under condition of optimal water supply, during soil water depletion, and during recovery from drought-stress. The plants were grown under a rainshelter in large containers with 2-m2 surface area. Control plants received water throughout the growth period. In Expt. 1, transient drought was imposed by interrupting water supply completely for 22 days. During the 33-day period of drought treatment in Expt. 2, the stressed plants received half the amount of water that was given to the control plants (irrigations 2–3 times per week).

During soil water depletion, stomatal conductance of the canopy was reduced earlier and more than photosynthesis. This resulted in a lower internal carbon dioxide concentration in the leaves of stressed plants and a higher ratio between photosynthesis and stomatal conductance. The value of that ratio increased as soil water potential dropped.

Water-use efficiency ( ) increased during drought stress. The cultivar Bintje showed a larger ratio between photosynthesis and stomatal conductance of the canopy and a higher than cv. Saturna, both for optimal water supply and during drought stress.

Photosynthesis and conductance of the canopy started to recover immediately upon rewatering, even when relative values had declined to 20–30% during the preceding stress period. After release from stress, the leaves in the top layer of the canopy had a higher stomatal conductance in treated plants than in control plants.  相似文献   


20.
不同生育期玉米干旱-复水补偿效应的品种差异研究   总被引:4,自引:1,他引:4  
以抗旱性不同的两个玉米品种郑单958和户单4号为材料,研究不同生育期干旱-复水对产量和水分利用效率的影响。结果表明,各生育期干旱-复水后,两个品种产量均低于对照处理,尤以扬花期干旱-复水最低;两个品种水分利用效率在扬花期干旱-复水最低;郑单958的产量、水分利用效率均高于户单4号,两者耗水量基本相等。分析两个品种株高、叶面积指数、干物质积累等在复水之后的变化表明,各生育期干旱-复水后,两个品种均存在一定的补偿效应,且郑单958的补偿效应明显较强。因此,郑单958在干旱-复水后补偿能力强,从而保持较高的产量和水分利用效率。  相似文献   

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