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1.
Finite quantities of water were applied at different growthstages of groundnut stands (Arachis hypogaea L.) grown in controlledenvironment glasshouses. Soil moisture deficits were imposedbetween sowing and pod initiation or between pod initiationand final harvest by withholding or applying water. Effectson assimilate production and partitioning and plant water relationswere examined. Leaves were the primary sites of 14CO2 fixation, though theircontribution generally declined late in the season, whereasfixation by stems was initially low but increased sharply whenstress was released in the late-irrigated stands. 14C-fixationby stem apices and pegs also rose sharply following irrigationof the late-stressed stands. Leaves were the primary source of assimilates, though translocationtended to decrease as the season progressed, even in the late-irrigatedstands. Stems were initially the major sinks, but their sinkactivity disappeared almost completely when stress was releasedin the late-irrigated stands. Assimilate import by stem apicesdeclined progressively and pod sink activity was negligiblein the late-stressed stand, but both increased markedly whenearly-season stress was released. Leaf water status showed marked diurnal variation, whereas pegsshowed less variation and maintained much higher turgor levels,largely because of their lower solute potentials. Marked osmoticadjustment occurred in expanding but not in mature leaves, allowingthem to maintain higher turgor levels during periods of severestress. This adjustment was rapidly lost when stress was released.The observed changes in assimilate production and partitioningpreceded detectable changes in bulk turgor levels. Implications for growth, development and yield are discussed. Key words: Groundnut, irrigation, partitioning, water status  相似文献   

2.
Stands of groundnut were grown in four glasshouses with themaximum saturation deficit (D) of the air limited to 1.0, 2.0,2.5 or 3.0 kPa. The soil was near field capacity when plantsemerged and no water was applied thereafter. In a fifth glasshouse,a stand was grown at low D on soil irrigated to field capacityevery few days. Developmental processes such as timing of flowering, peggingand pod formation were unaffected by D, but the numbers of branches,flowers and pegs were reduced in the drier treatments. Measurementsduring the first 30 d showed that in the drier treatments leafgrowth was reduced, and the partitioning of dry matter intoroots was enhanced. In the unirrigated stands, dry matter production in shoots wasreduced by 40 per cent as the maximum D increased from 1.0 to3.0 kPa. Growth was affected through reductions both in leafarea (and therefore light interception) and in the productivityper unit of light intercepted. These responses to D and soilwater were linked to changes in bulk water potential of leaves. Productivity per unit of water transpired (q) decreased withincreasing D. The product of q and the mean daytime value ofthe difference in vapour pressure between leaf and air was moreconservative than q, and ranged from 3.1 to 5.6 g kPa kg–1. Groundnut, Arachis hypogaea L., saturation deficit, growth, development, light interception, water use efficiency  相似文献   

3.
A recently-developed solution culture technique was used tostudy the effects of aeration and calcium (Ca) on groundnut(ArachishypogaeaL.) pod development. Two experiments were conductedwith seven groundnut lines, TMV-2, Chico and A116L4 (Spanish),CBRR4 (Valencia), A125L25 (ValenciaxSpanish), and Shulamit Strain1 (SH-1) and Virginia Brunch Strain 1 (VB-1) (Virginia). Plantswere grown in a potting mix, and the attached gynophores culturedin darkened polycarbonate jars containing nutrient solution.Non-aeration of solution prevented pod development, but podsand seeds of all lines developed in aerated, darkened nutrientsolutions (ionic strength approx. 9 mM). Normal pods and seedswere produced by TMV-2, Chico and CBRR4, but constricted podsdeveloped in SH-1 and VB-1. A secondary gynophore developedbetween the basal and apical seed compartments in A116L4 andA125L25, and in VB-1 at high Ca (500–2500 µM) insolution. The secondary gynophores were similar to those producedin otherArachisspp. but not usually found in cultivated formsofA. hypogaea.Septate and non-septate hairs developed on submergedgynophores and pods, but were sparse on those of SH-1 and VB-1.The magnitude of the effects of aeration and Ca concentrationon pod initiation and morphogenesis differed in experimentsconducted in summer and winter and among the lines tested.Copyright1998 Annals of Botany Company Arachis hypogaeaL., calcium, groundnut, pod morphology, secondary gynophore, solution culture.  相似文献   

4.
Summary Field experiments were conducted during 1979 and 1980 summer seasons on sandy loam soils of low moisture retentive capacity to study the effect of high frequency irrigation at different levels of N on groundnut yield and nutrient uptake (NPK). Four irrigation frequencies (irrigation at 2, 4, 6 and 8 cm cumulative can evaporation, corresponding to irrigation once in 3, 5, 7 and 10 days respectively) and four levels of nitrogen (0, 20, 40 and 60 kg N/ha) were tested in a factorial randomized block design with three replications. Pod yield of groundnut was maximum (3,293 kg/ha) when irrigations were scheduled at 4 cm cumulative can evaporation (once in 5 days). Addition of N did not increase the pod yield. N and P uptake by the crop was maximum (180 kg N and 18 kg P/ha) with high frequency irrigation of scheduling irrigation at 4 cm cumulative can evaporation. Highest uptake of N (183 kg/ha) and P (19 kg/ha) was with a combination of 20 kg N/ha and high frequency irrigation (4 cm CCE). K uptake was low with low irrigation frequency, while it was highest (67 kg K/ha) at 20 kg N/ha.  相似文献   

5.
In the developing pods of two genotypes of groundnut, putrescine,cadaverine, spermidine and spermine decreased in the fruit walland increased in the developing seed. ADC activity also followedthe same pattern. On germination all the polyamines decreasedin the cotyledons and increased progressively in the growingembryonic axis. The level of all the polyamines showed differencesbetween both the cultivars during seed development and germination. Arachis hypogaea L, genotypes, pod development  相似文献   

6.
The effects of elevated atmospheric CO2, alone or in combinationwith water stress, on stomatal frequency in groundnut (Arachishypogaea (L.) cv. Kadiri-3) were investigated. CO2 exerted significanteffects on stomatal frequency only in irrigated plants. Theeffects of drought on leaf development out weighed the smallereffects of CO2 concentration, although reductions in stomatalfrequency induced by elevated atmo-spheric CO2 were still observed.When stands of groundnut were grown under irrigated conditionswith unrestricted root systems, an increase in atmospheric CO2from 375 to 700 ppmv decreased stomatal frequency on both leafsurfaces by up to 16% in droughted plants, stomatal frequencywas reduced by 8% on the adaxial leaf surface only. Elevatedatmospheric CO2 promoted larger reductions in leaf conductancethan the changes in stomatal frequency, indicating partial stomatalclosure. As a result, the groundnut stands grown at elevatedCO2 utilized the available soil moisture more slowly than thosegrown under ambient CO2, there by extending the growing period.Despite the large variations in cell frequencies induced bydrought, there was no treatment effect on either stomatal indexor the adaxial/abaxial stomatalfrequency ratio. The data suggestthat the effects of future increases in atmospheric CO2 concentrationon stomatal frequency in groundnut are likely to be small, especiallyunder conditions of water stress, but that the combination ofassociated reductions in leaf con-ductance and enhanced assimilationat elevated CO2 will be important in semi-arid regions Key words: Arachis hypogaea L, Leguminosae, groundnu, stomatal frequency, CO2, drought  相似文献   

7.
Gas exchange parameters for the potato (Solanum tuberosum L.,cv. ‘Desiree’) crop were measured under field conditions.Nitrogen nutrition was found to have a positive effect on photosynthesisthroughout the growing season. The gas exchange data and thechlorophyll content in the leaves indicated that this effectwas essentially in the mesophyll. Stomatal resistance increasedas photosynthetic rate decreased, but substomatal CO2 concentration(Ci) was not affected by nitrogen treatments. Long term effects of water deficit on photosynthetic capacitywere also mostly mesophyllic in origin. A reduction in photosyntheticrate was observed after a period of moisture stress and alsoafter relief of drought by irrigation, indicating a limitedcapacity for recovery. A short term afternoon increase in stomatalresistance, associated with lower Ci values, occurred afterlong periods without irrigation. Leaf water potential was affectedby irrigation frequency, but less strongly than the gas exchangeparameters. Mesophyll activity and stomatal behaviour were bothaffected by water stress and by nitrogen deficiency, whereasCi values were not affected in most cases. Solanum tuberosum L, photosynthesis, mesophyll, stomata, irrigation frequency, nitrogen deficiency, chlorophyll, leaf water potential  相似文献   

8.
Intercropping groundnut with sorghum at a 3:1 ration has given lower AUDPC (1018) with a mean pod yield of 1868 kg/ha, and was found significant in reducing the PBND (34.2%) compared to sole groundnut (AUDPC of 1545 mean pod yield of 1407 kg/ha, 52% PBND). In groundnut intercropped with pulses, groundnut + redgram (5:1) was found to be effective in reducing PBND to an extent of 10% and recorded higher equivalent pod yield of 2236 kg/ha with 1014 AUDPC compared to sole groundnut (AUDPC 1078, 63.44% PBND; mean pod yield of 1663 kg/ha). The higher incidence of PBND was recorded in the treatments involving greengram, blackgram and soybean and it was also reflected in realising higher values of AUDPC.  相似文献   

9.
Stands of groundnut (Arachis hypogaea L.), a C3 legume, weregrown in controlled-environment glasshouses at 28 °C (±5°C)under two levels of atmospheric CO2 (350 ppmv or 700 ppmv) andtwo levels of soil moisture (irrigated weekly or no water from35 d after sowing). Elevated CO2 increased the maximum rate of net photosynthesisby up to 40%, with an increase in conversion coefficient forintercepted radiation of 30% (from 1–66 to 2–16g MJ–1) in well-irrigated conditions, and 94% (from 0–64to 1·24 g MJ–1) on a drying soil profile. In plantswell supplied with water, elevated CO2 increased dry matteraccumulation by 16% (from 13·79 to 16·03 t –1) and pod yield by 25% (from 2·7 to 3·4t ha–1).However, the harvest index (total poddry weight/above-grounddry weight) was unaffected by CO2 treatment. The beneficial effects of elevated CO2 were enhanced under severewater stress, dry matter production increased by 112% (from4·13 to 8·87 t ha–1) and a pod yield of1·34t ha–1 was obtained in elevated CO2, whereascomparable plotsat 350 ppmv CO2 only yielded 0·22 t ha-1.There was a corresponding decrease in harvest index from 0·15to 0·05. Following the withholding of irrigation, plants growing on astored soil water profile in elevated CO2 could maintain significantlyless negative leaf water potentials (P<0·01) for theremainder of the season than comparable plants grown in ambientCO2, allowing prolonged plant activity during drought. In plants which were well supplied with water, allocation ofdry matter between leaves, stems, roots, and pods was similarin both CO2 treatments. On a drying soil profile, allocationin plants grown in 350 ppmv CO2 changed in favour of root developmentfar earlier in the season than plants grown at 700 ppmv CO2,indicating that severe waterstress was reached earlier at 350ppmv CO2. The primary effects of elevated CO2 on growth and yield of groundnutstands weremediated by an increase in the conversion coefficientfor intercepted radiation and the prolonged maintenance of higherleaf water potentials during increasing drought stress. Key words: Arachis hypogaea, elevated CO2, water stress, dry matter production  相似文献   

10.
The response of leaf area expansion to atmospheric saturationdeficit (SD) and soil moisture deficit was examined in termsof leaf water potential (1) and turgor potential (p), as partof a wider study of the effects of SD on groundnut growth. Standsof plants were grown at four levels of SD and without irrigationin controlled environment glasshouses. A fifth stand was grownat low SD on soil kept irrigated to field capacity. Large saturation deficits accelerated the depletion of soilmoisture reserves in the unirrigated stands and greatly reducedleaf area index, particularly in the driest treatment. Leafnumber per plant and leaf size both decreased as SD increased,but the effect on leaf size was greater than on number. SD hadless effect than soil water deficit on leaf production. Turgorpotential and leaf extension rate (R) were both reduced at highsaturation deficits and R was linearly related to p between0900 and 1600 h. However, leaf extension rate and turgor potentialwere poorly correlated between 0400 and 0700 h in the driesttreatment. Arachis hypogaea L., groundnut, saturation deficit, leaf growth, canopy development  相似文献   

11.
Summary Three levels of irrigation, three plant densities and three fertiliser schedules were tested in 33 factorial confounded design with two replications in winter on sandy loam soils of Tirupati campus of Andhra Pradesh Agricultural University. Pod yield did not vary due to the plant densities and the fertiliser schedules when the crop was sown in optimum time during 1980. When the sowings were delayed, as in 1979, 444000 plants per ha and 60 kg N ha−1, 40 kg P ha−1 and 100 kg K ha−1 was optimum. Scheduling irrigation at 25 or 50% DASM (depletion of available soil moisture) was optimum for the groundnut crop. There was no difference in the uptake of NPK due to irrigations at 25 and 50% DASM in both the years. Low plant density was as effective as high plant density for efficient use of fertilisers. Uptake of NPK by the crop was relatively high at higher fertiliser levels. However, this higher uptake did not contribute to high pod yield, probably due to utilisation of absorbed nutrients for rank vegetative growth.  相似文献   

12.
Summary Eight characters related to nitrogen fixation and pod development measured 30 days after flowering were evaluated for their correct grading of the relative yield performance of 17 genetically diverse lines of groundnut (Arachis hypogaea L.). Each line was assigned a high or low yield status based on its pod yield, shelling percentage, and 100-kernel weight. Seventeen character combinations were examined for their relative merit in correct identification of the yield status of lines. The character sets, nitrogenase activity alone or in combination with nitrogen percent or shoot weight identified the status of 77% of lines correctly. The extent to which various characters accounted for the variation in pod yield was also checked by multiple regression analysis. While the character combination, nitrogen percent plus leaf area explained 75% of variation in pod yield, nodule mass, nitrogenase activity, and leaf area occurred in some other combinations that explained yield variation to a lesser extent. These analyses point to the profitability of involving crop physiological traits such as leaf area and nitrogen percent in selecting for relative yield performance in groundnut.IARI Regional Station, Tutikandi, Simla 171004, IndiaNational Research Center for Groundnut, Timbawadi, Junagadh 362015, India  相似文献   

13.
The Performance of Phragmites communis Trin. in Relation to Water-supply   总被引:1,自引:0,他引:1  
HASLAM  SYLVIA M. 《Annals of botany》1970,34(4):867-877
Water table is one of the factors controlling the distributionand performance of Phragmites communis Trin. Dense stands normallylose more water through evapotranspiration than is suppliedby rain. However, Phragmites grows in a wide range of regimes,and is limited, in Britain, more by nutrient status than bywater depth at its wetter limit, and more by competition thanby water shortage at its drier limit. Rhizome level and the level of bud initiation are affected bywater table, but performance of aerial shoots need not be affectedby this, in the ordinary water regimes. Soil aeration, in therange found in East Anglia, does not affect performance, butif cut (or broken) reed is flooded, thus impeding aeration,performance decreases. Once a seasonal pattern of water-levelfluctuations is established, departure from this (causing dryingin a season the stand is normally flooded) disturbs the growthcycle and lowers the yield.  相似文献   

14.
Effects of Water Stress on Fruit Quality Attributes of Kiwifruit   总被引:5,自引:0,他引:5  
Four-year-old kiwifruit vines (Actinidia deliciosa(A. Chev.)C. F. Liang et A. R. Ferguson var.deliciosacv. Hayward) werestudied to determine response of the plant and effects on fruitquality when irrigation water was withheld either early or latein the growing season. The greatest effect on fruit growth occurredwhen water was withheld early in the season. Harvest weightof fruit from early-stressed vines was approx. 25% less thanthe weight of fruit on control vines. Early season water stressresulted in a transient increase in concentrations of solublecarbohydrates in both leaves and fruit. This was accompaniedby a reduction in stomatal conductance of the leaves. Starchlevels in leaves but not fruit were reduced by both stress treatments.Concentrations of sucrose at harvest in fruit from vines stressedlate in the season were markedly higher than in other fruit,and softness of the fruit was unaffected. These differenceswere maintained through the 12 weeks in cool storage after harvest.Withholding irrigation water to kiwifruit vines late in theseason may prove a useful management tool to manipulate somequality attributes of the fruit.Copyright 1998 Annals of BotanyCompany Kiwifruit;Actinidia deliciosa; water stress; fruit quality; soluble solids.  相似文献   

15.
Field, greenhouse and laboratory investigations were conducted to determine the effect of four dinitroaniline herbicides on rhizobia, nodulation and nitrogen fixation of four groundnut cultivars. Benefin, dinitramine and nitralin used at recommended levels decreased nodule dry weight, nitrogenase activity and total nitrogen of groundnut tops and pod yield in three cultivars Kadiri 71-1, Kadiri-2, ICGS-11 and not for a fourth cultivar, Kadiri-3 of groundnut (Arachis hypogaea L.), but fluchloralin used at the recommended level increased the nodulation rate, nitrogenase activity and total nitrogen of groundnut tops and pod yield compared to untreated plants. Studies were conducted in vitro to determine the relative toxicity of the herbicides on four Rhizobium strains isolated from the nodules of four cultivars of groundnut. It was found that various strains of rhizobia differ in their sensitivity to different rates of the herbicides tested. Carbon dioxide exchange rate (CER) of all the cultivars which received herbicide treatment was measured at different time intervals to determine the relationship between photosynthesis and inhibition of nodulation. The lack of adverse effect on the CER of four cultivars when treated at recommended concentrations indicated that nitrogen fixation was affected in cultivars Kadiri 71-1, Kadiri-2 and ICGS-11 due to inhibition of nodulation.  相似文献   

16.
Differentiation to a specialized function in plant tissue isassociated with an increase in the DNA content of the cellsover the diploid state. Using flow cytometry, ploidy levelswere assessed during pod development in three white lupin genotypesunder three environmental conditions and in other lupin speciesand temperate grain legumes in one environmental condition.Endoreduplication was found in the pod walls of all genotypesstudied. Higher ploidy levels coincided with maximal growthof the pod. DNA replication was not related to the proportionof the pod that comprised walls. Endoreduplication also occurredin other temperate grain legumes with at least two DNA duplicationsduring the development of the pod walls. The biological significanceof endoreduplication in the pod walls of grain legumes is unknown,but could be related to the storage function of these organs.Copyright2000 Annals of Botany Company Lupinus species, Pisum sativum, Phaseolus vulgaris, Vicia faba, pod wall development, ploidy level, flux cytometry, Bis-benzimide Hoechst 33258  相似文献   

17.
Macroptilium atropurpureum cv. Siratro was grown in large soilbeds with a constant water table below, developing a dawn leafwatêr potential of --0.25 MPa. Water stresses equivalentto -0.7 or -1.0 MPa were developed over 14 d, causing reducedstem and bud elongation, leaf expansion, and bud differentiationand survival. Apex size, the proportion of buds which were floralor vegetative, the early phases of floral initiation, and seedformation on advanced inflorescences were little affected duringthe water deficit period. Upon rewatering previously stressed plants showed increasesrelative to control plants in the rates of shoot appearance,leaf expansion and new node appearance. The ratio of buds becomingfloral was independent of watering treatment, and the enhancedrate of floral bud production in the previously-stressed treatmentswas due to higher rates of total bud differentiation which persistedfor up to six weeks after rewatering. Survival of floral budswas reduced by previous stress, but number of flowers per inflorescence,pod setting, seed number per pod and 100-seed weight were independentof treatment. Seed production was controlled by inflorescencedensity. Rate of seed production was independent of treatmentduring water deficit and four weeks subsequently, and was thenenhanced by 46 and 54 per cent relative to the control in the–0.7 and –1.0 MPa treatments respectively. Macroptilium atropurpureum, Siratro, floral initiation, flowering, seed production, water stress, bud development  相似文献   

18.
The Nature and Duration of Gene Action for Vernalization Response in Wheat   总被引:1,自引:1,他引:0  
Four near-isogenic lines of wheat were studied to determinethe nature and duration of gene action for vernalization responseunder 2 weekly vernalization periods from 0 to 10 weeks. With time to floral initiation the Vrn 1 Vrn 2 and Vrn 1 vrn2 genotypes showed a cumulative response whereby days to floralinitiation decreased as the period of vernalization increased.The vrn 1 Vrn 2 and the vrn 1 vrn 2 genotypes also showed acumulative response for periods of vernalization less than 6weeks for the former and 8 weeks for the latter. Days to earemergence was closely related to days to floral initiation dueto the constancy of the period from floral initiation to earemergence across all lines and treatments and, consequently,they gave similar measures of the relative strength of vernalizationresponse. It appears that genes for vernalization response ceaseto act after floral initiation. The implications of these findings to breeding for increasedadaptability and yield in wheat are discussed. Triticum aestivum, wheat isogenic lines, vernalization, floral initiation, ear emergence, gene action  相似文献   

19.
高水位地区作物生长关键期采用微咸水或咸水灌溉被证明在一定条件下可以起到增产正效应,但同时却存在着土体盐分积累及其对下茬或次年种植影响的生态负效应.为探讨消除或抑制微咸水或咸水灌溉对土壤盐分积累的生态负效应,保证作物种植增产的正效应,本文在河北近滨海高水位盐碱区开展了为期2年的试验研究,探讨了旱季微咸水或咸水灌溉带来的盐分异位积累与离子分布变化特征,分析了雨季关键期暗管适时排盐对土壤盐分的立体调控生态效应.结果表明:旱季咸水灌溉后土壤经历“积盐-脱盐-二次积盐”3个阶段;灌溉初期,1 g·L-1咸水灌溉处理下0~50 cm土体脱盐,土壤含盐量随土壤深度增加而增加,HCO3-含量增加,其他离子含量降低;6与13 g·L-1咸水灌溉处理下0~50 cm土体积盐,土壤含盐量随土壤深度增加而降低,HCO3-含量降低,其他离子含量增加;雨季暗管适时立体调控脱盐效果显著,土壤脱盐率达16.0%~45.7%,同降雨量下,降水分布越集中,脱盐效果越好;周年时间尺度上,咸水灌溉小区土壤积盐量小于对照区;咸水灌溉处理小区冬小麦产量显著高于对照处理,1 g·L-1 处理高于6与13 g·L-1处理.  相似文献   

20.
Groundnut (Arachis hypogaea L.) productivity in India is low, because of many problems beset in its cultivation. One of the serious problems are weeds. Groundnut yield losses due to weeds have been estimated as high as 24 to 70 percent. This has created a scope for using herbicides in groundnut crop. A field investigation was carried out during kharif (rainy) season of 2001-2002 on a sandy loam soil at College Agronomy Farm, B.A. College of Agriculture, Gujarat Agricultural University, Anand, India to study the effect of weed management practices and Rhizobium inoculation on growth and yield of groundnut (Arachis hypogaea L.). Ten weed control treatments, comprising four treatments of sole application of fluchloralin, pendimethalin, butachlor and metolachlor, respectively each applied at 1.0 kg ha(-1); four treatments comprising of an application of the same herbicides at the same levels coupled with one hand weeding at 30 DAS; one weed-free treatment (hand weedings at 15, 30, 45 DAS); and one unweeded control. All 10 treatmets were combined with and without Rhizobium inoculation (i.e. a total of 20 treatment combinations) under a factorial randomized complete block design (FRBD) with four replications. Minimum weed dry matter accumulation (70 kg/ha) with higher weed control efficiency (90.70%) was recorded under an integrated method i.e. pendimethalin at 1.0 kg ha(-1) + hand weeding at 30 DAS, which also resulted in maximum pod yield (1773.50 kg ha(-1)). This treatment was comparable to fluchloralin applied at 1.0 kg ha(-1) combined with hand- weeding at 30 DAS. Weedy conditions in the unweeded control treatment reduced pod yield by 29.90-35.95% as compared to integrated method. Significantly higher pod yield was obtained with Rhizobium inoculation than the mean value of all treatments without inoculation. For most agronomical parameters examined, Rhizobium inoculation and weed control treatments were independent in their effect.  相似文献   

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