共查询到18条相似文献，搜索用时 453 毫秒
1.
2.
3.
甘蓝型油菜幼苗对短期氧化胁迫的光合响应 总被引：1，自引：0，他引：1
在盆栽的甘蓝型油菜中双11号幼苗叶片上涂抹氧化剂甲基紫精（MV）,分析测定0～24h内叶片叶绿素含量和光合参数的变化,以分析光氧化胁迫影响油菜光合速率的关键因子。结果显示,油菜受到氧化胁迫后,叶绿素含量、净光合速率（Pn）、气孔导度（Gs）、胞间二氧化碳浓度（Ci）、蒸腾速率（Tr）、水分利用率（WUE）均下降,降低幅度随着涂抹时间的延长而增大;气孔限制值（Ls）却随着氧化胁迫时间的增加而升高。叶绿素组分和光合参数对氧化胁迫的敏感响应时间差异较大,胞间二氧化碳浓度和气孔限制值在2h即受到显著抑制,而水分利用率的响应相对滞后,为24h。回归分析表明氧化胁迫影响油菜净光合速率的最直接光合因素是气孔限制值。 相似文献
4.
低磷和干旱胁迫对不同基因型大豆光合生理特性的影响 总被引：1，自引：0，他引：1
采用盆栽培养的方法,研究了缺磷和干旱对鼓粒期磷高效基因型大豆黑河27,磷中效基因型大豆黑农43和磷低效基因型大豆黑河29的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Cs)、胞间CO2浓度(Ci)、气孔限制值(Ls)、水分利用率等光合生理性状的影响.结果表明:低磷和干旱胁迫降低了3个基因型大豆叶片的净光合速率、蒸腾速率、气孔导度和气孔限制值;相反,胞问CO2浓度呈卜升趋势,说明光合速率的降低受非气孔因素的限制;低磷和干旱胁迫处理降低了大豆叶面积、叶绿素含量,变化为磷低效基因型＞磷中效基因型＞磷高效基因型,说明缺磷和长期干旱能使大豆叶而积降低,叶绿素降解,减少了光合叶而积和光能吸收,影响光合作用.与磷低效大豆相比,磷高效大豆具有在干旱条件下对CO2的同化和水分利川能力上的优势.磷高效大豆在水分逆境下叶片能保持较高的光合速率并提高对水分的利用效率,显示其对干旱有较强的耐受性. 相似文献
5.
为了解干旱后燕麦解剖结构的变化,以燕麦品种白燕2号为材料,通过盆栽控水试验,设置正常供水、轻度干旱和重度干旱三个不同水分处理(土壤含水量分别为田间持水量的75%、60%和45%),研究了干旱胁迫对燕麦叶片渗透调节物质含量、气孔和叶肉细胞超微结构的影响。结果表明,正常水分条件(对照)下,燕麦叶片脯氨酸和可溶性糖含量较低,表皮细胞皱褶,气孔关闭或微张,叶肉细胞内细胞器形状规则,结构清晰。与对照相比,轻度干旱胁迫下,燕麦叶片脯氨酸和可溶性糖含量增加,叶片表皮细胞饱满,气孔开启度较大,叶绿体形状变圆,近球状,线粒体外被膜膨胀,但结构未见明显损伤;重度干旱胁迫下,叶片脯氨酸和可溶性糖含量极显著增加,表皮细胞干瘪,气孔保卫细胞膨胀,气孔关闭,气孔器下陷。重度干旱胁迫下,燕麦叶绿体和线粒体受到的损伤较大,叶绿体内基粒、基质类囊体降解,出现较大的空腔;线粒体外被膜断裂,内含物流失;细胞核染色质凝聚,叶绿体之间出现嵌合现象。因此,干旱胁迫能诱导燕麦叶片渗透调节物质的积累和细胞超微结构的改变,渗透调节物质增幅和细胞超微结构的破坏程度随着土壤有效水分含量的降低而上升,但在细胞超微结构上也出现抗性反应,表明燕麦具有较强的抗旱性。 相似文献
6.
水分胁迫对棉花气孔阻力及光合速率的影响 总被引：1，自引：0，他引：1
１９８４～１９８５年，研究了田间滴灌条件下，水分胁迫对棉花气孔阻力及光合速率的影响。水分胁迫以水势表示，中午叶片水势最小。在两个生理阶段，水势分别保持在两个水平（－１．６和－２．４ＭＰａ）。水分胁迫导致气孔阻力增大，光合速率降低。当植株受水分胁迫时，气孔阻力与光照强度间的相关度较低。光合速率与气孔阻力间呈指数曲线关系。在无胁迫或轻度胁迫下，气孔限制光合进程；而在严重胁迫下，叶肉阻力是降低光合速率的主要因素。在水份胁迫植株中，叶肉阻力比气孔阻力增长更快，这与叶片内ＣＯ２浓度（Ｃｉ）较高及光合速率与Ｃｉ的比率较低有关。在适度水份胁迫下，最大光合速率的叶片的叶龄较小，而在严重胁迫下，所有叶片光合速率较低。 相似文献
7.
《中国油料作物学报》2015,(5)
为了明晰缺钾胁迫下光合速率下降的主导因素及其作用机制,在田间条件下设置正常供钾处理(+K)和缺钾处理(–K),采用气体交换和叶绿素荧光联合测定技术以及透射电镜技术,研究缺钾胁迫时越冬期甘蓝型油菜品种浙油601的光合特性及叶绿体超微结构。结果表明,缺钾胁迫时叶片光合速率下降了45.1%。尽管缺钾胁迫下叶片气孔导度(gs)明显降低,但其胞间CO2浓度(Ci)增加了66μmol CO2·mol-1,气孔限制值(Ls)减小了45.7%,说明气孔因素并非缺钾胁迫下油菜叶片Pn下降的主要原因。进一步的叶绿素荧光参数测定结果表明,缺钾胁迫导致油菜越冬期叶片PSII潜在光化学效率(Fv/Fm)和实际光化学效率(ΦPSII)显著下降,说明光系统II反应中心受损;并且缺钾胁迫下油菜叶片叶绿体的长度降低了15.1%、叶绿体厚度增加了22.7%、叶绿体到细胞壁的距离增加了56.1%。由此可见,缺钾胁迫下越冬期油菜叶绿体结构改变及光系统反应中心受损等非气孔因素导致叶片光合速率下降。 相似文献
8.
《中国油料作物学报》2016,(6)
为探讨油菜光合机构对干旱胁迫的响应,研究了2个抗旱性不同的油菜(Brassica napus L.)品种在干旱胁迫下农艺性状、气体交换参数、叶绿素荧光参数、叶绿体超微结构及Rubisco活性等指标的变化。结果表明,干旱胁迫下,相对增长率、总干重、叶面积和叶片相对含水量降低,而根冠比增加;净光合速率、蒸腾速率、气孔导度和胞间CO2浓度降低,而气孔限制值增加;PSⅡ最大光能转换效率、PSⅡ实际光能转换效率、光化学淬灭和电子传递效率降低,而非光化学淬灭系数增加;两品种的叶绿体超微结构遭到不同程度破坏;且叶绿素含量和Rubisco活性降低,脯氨酸和可溶性糖的含量增加。敏感型品种秦优8号光合机构遭受干旱的破坏程度明显大于抗旱型品种Q2。 相似文献
9.
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
10.
水分胁迫对灌浆期燕麦叶片光合特性的影响 总被引：4，自引：0，他引：4
在盆栽条件下,研究了灌浆期燕麦在水分胁迫条件下光合有效辐射对叶片净光合速率、胞间CO2浓度及气孔导度的影响。结果表明,净光合速率对光合有效辐射的响应均呈直角双曲线变化,水分胁迫不仅使净光合速率减小,而且光补偿点、光饱和点及呼吸速率也明显降低;水分胁迫还使叶片胞间CO2浓度、气孔导度减小,且随光合有效辐射增强减小幅度增大;分析认为,气孔导度和光合速率直接影响胞间CO2浓度变化,但在水分胁迫条件下前者则是影响胞间CO2浓度变化的主要因素,也就是水分胁迫致使净光合速率下降更主要是由于气孔因素作用的结果。 相似文献
11.
Effects of water stress on photosynthesis and chlorophyll fluorescence of five potato cultivars 总被引：4，自引：0，他引：4
Summary Reduction of leaf photosynthesis due to water stress has been analyzed into various components and genetic variation in these
components has been evaluated. Five potato cultivars were grown on nutrient solution in a conditioned glasshouse. Water stress
was imposed by adding polyethylene glycol to the nutrient solution. Photosynthesis, transpiration and chlorophyll fluorescence
were measured on intact leaves during the stress period and after recovery from the stress.
Water stress reduced photosynthesis, initially as a consequence of stomatal closure, but after 3 days increasingly by inhibiting
directly the photosynthetic capacity (mesophyll limitation). Stomatal closure correlated with the reduction in photosynthesis,
but it was not the sole cause of this reduction because the internal CO2 concentration in the leaves was not affected by water stress, indicative of inhibitory factors other than stomatal ones.
Chlorophyll fluorescence emission suggested that the Calvin cycle was inhibited, while quantum efficiency was not affected
at 17°C. Increasing the temperature to 27°C reduced quantum efficiency but only in the stress environment. The recovery of
young leaves after relief of the stress was associated with a lower stomatal conductance but a higher mesophyll conductance
compared with the control, which caused a low internal CO2 concentration and probably invoked photo-inhibition and leaf damage.
Cultivar differences in photosynthetic rate were highly significant under both optimal and stress conditions, and corresponded
with differences in mesophyll conductance. 相似文献
12.
不同土壤肥力下旱后复水对冬小麦光合特性及水分利用效率的影响 总被引：2，自引：0，他引：2
为给冬小麦节水高产栽培提供理论依据,采用盆栽试验,研究了不同土壤肥力下返青后干旱及拔节期复水对冬小麦光合特性和水分利用效率的影响。结果表明,同一土壤水分条件下,光合速率、蒸腾速率、气孔导度、胞间CO2浓度均随土壤肥力的降低而降低;同一土壤肥力下,光合速率、蒸腾速率、气孔导度、胞间CO2浓度均随干旱程度的增加而降低。干旱胁迫复水24 h后,光合速率、蒸腾速率、气孔导度、胞间CO2浓度均出现了补偿或超补偿效应,但中度干旱恢复度大于重度干旱。光合速率以HA处理（高肥力、最大田间持水量的85%）最高,单叶水分利用效率在干旱胁迫下和复水24 h后均以HB处理（高肥力、最大田间持水量的55%）最高。以上结果说明,冬小麦返青期中度干旱条件下,高肥力土壤有利于复水后光合系统恢复和单叶水分利用效率提高,而重度干旱下贫瘠土壤应减少基肥的施入量。 相似文献
13.
盐胁迫对不同水稻品种光合特性和生理生化特性的影响 总被引：13，自引：0，他引：13
用2个耐盐水稻品种和2个盐敏感型水稻品种为材料,研究盐胁迫对水稻植株生物量积累、光合特性等生理特性的影响。结果表明,在盐胁迫条件下,耐盐水稻品种和盐敏感型水稻品种地上和根系的干鲜质量均呈下降趋势,其中,以盐敏感型水稻品种的地上部鲜质量与根系干质量的下降最为显著。盐胁迫条件下,水稻叶片的净光合速率（Pn）、气孔导度（Gs）、蒸腾作用（Tr）和表观叶肉导度（AMC）均呈不同程度的下降趋势。其中,耐盐水稻品种Pn、Gs、Tr和Pn/Ci的下降均低于盐敏感型水稻品种。同时,耐盐品种水分利用效率（WUE）也高于盐敏感型品种。盐胁迫条件下,耐盐水稻品种和盐敏感型水稻品种的胞间二氧化碳浓度（Ci）变化并不明显,气孔限制百分率（Ls）均较低,品种间差异也不显著,而表观叶肉导度显著下降,由此推测盐胁迫条件下Pn的下降并非因为气孔的限制,而与RuBPCase活性的下降有关。盐胁迫条件下水稻叶片和根系的渗透性调节物质脯氨酸、总氨基酸和可溶性糖含量上升,其中以可溶性糖含量上升最为显著（P＜0.01）。盐胁迫下叶片保护酶SOD、POD和CAT活性增强,膜透性增强,丙二醛含量增加,同时,根系活力下降。 相似文献
14.
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
15.
《Plant Production Science》2013,16(3):252-255
AbstractWe investigated the effect of drought stress on biomass productivity of newly established Erianthus ravennae (L.) Beauv. This species has recently drawn great attention as a novel cellulosic energy crop because of its excellent tolerance against various environmental stresses, but the shoot dry weight of the newly established E. ravennae was significantly decreased under drought compared to irrigated condition. A significant correlation between shoot dry weight and stem number suggested that the drought-induced decrease in stem number was ascribable to the reduced shoot dry weight in the drought condition. Decrease in soil water content was coincident with mid-day decrease in stomatal conductance, suggesting that limitation of CO2 diffusion into leaf due to lower stomatal conductance in the drought condition caused decrease in photosynthesis followed by suppression of stem number. The present study suggested that E. ravennae was susceptible to drought, at least, in the first establishment year. 相似文献
16.
《Field Crops Research》1999,62(1):35-52
A field study was conducted to investigate the effect of intermittent soil drying on resulting non-hydraulic and hydraulic root signals, leaf gas exchange, leaf growth, day of heading, leaf osmotic adjustment and yield of wheat grown in sand and loam soils in lysimeters. A 40-day-drought treatment was imposed when the flag leaf started to emerge and was terminated close to maturity. Soil water content and soil water potential of various soil layers were measured using the neutron moderation method and tensiometers, respectively. Soil drying in the top soil layers induced increase in both xylem and bulk-leaf abscisic acid (ABA) content and reduced the stomatal conductance and leaf growth even before a measurable change in leaf water potential could be detected in droughted plants when compared with fully watered plants. Further, heading and flowering occurred 4 days earlier in the droughted than in the well-watered plants before any loss in leaf water potential had occurred as compared with the fully watered plants. When more severe drought reduced the leaf water status, further accumulation of leaf ABA occurred and transpiration decreased in addition to gradual osmotic adjustment and senescence of older leaves. The osmotic adjustment sustained leaf turgor pressure during soil drying. At severe drought, the osmotic adjustment at full turgor in the flag leaves was 0.85 MPa. In sand, the kernel dry weight increased and as a result similar grain yield was obtained in both the treatments. In loam which had more water available than sand, no significant reduction in the final yield was induced by the drought. It is concluded that (1) non-hydraulic root signals caused early drought adaptation at mild water stress by reducing leaf growth and stomatal conductance and hastening of heading and flowering; (2) osmotic adjustment sustained turgor maintenance and hence the yield-forming processes during moderate and severe water stress. 相似文献
17.
为了解钾肥对抗旱的生理影响，以抗旱性不同的两个油菜品种川油36（敏感）和油研57（耐旱）为材料，采用水培试验，调查干旱缺钾对油菜内源激素、光合作用和叶绿素荧光特性的影响。设置缺钾（0.01 mmol/L K2SO4）和正常钾肥（1.0 mmol/L K2SO4）两个梯度，加入7%的PEG6000模拟干旱，分别记为LK和NK处理。结果发现，干旱胁迫严重抑制油菜生长，不同钾肥水平对油菜生长和激素水平影响显著，与NK处理相比，LK处理下油菜生物量和叶片吲哚乙酸（IAA）、细胞分裂素（CTK）和油菜素内酯（BR）含量显著降低，而脱落酸（ABA）含量显著增加。干旱胁迫下钾肥水平对油菜光合作用影响显著，与NK相比，LK处理下油菜净光合速率、气孔导度、核酮糖-1,5-二磷酸羧化酶（RuBP羧化酶）活性、磷酸烯醇式丙酮酸羧化酶（PEPC）活性均显著降低。干旱胁迫下光系统I（PSI）P700最大变化（Pm）和光下P700最大变化（Pm'）显著降低，LK处理下Pm'显著低于NK处理，而PSI受体侧限制非光化学量子产量[Y(NA)]显著高于NK处理。干旱胁迫导致光系统II（PSII）最大光化学量子产量（Fv/Fm）显著降低，与NK处理相比，LK处理下Fv/Fm和PSII调节性能量耗散[Y(NPQ)]显著降低，然而非调节性能量耗散[Y(NO)]显著增加。LK处理下抗旱品种油研57叶片IAA含量、CTK含量、叶绿素含量、净光合速率和Fv/Fm显著高于川油36，表现出更高的生物量。综上，干旱缺钾会诱导ABA积累，抑制生长促进类激素IAA、CTK和BR的合成，抑制油菜生长。干旱缺钾条件下，RuBP羧化酶和PEPC酶活性显著降低，同时PSI受体侧过度还原，PSII调节性能量耗散减弱，非调节性能量耗散量子产量增加，造成PSI和PSII活性下降，导致油菜光合作用降低并限制油菜生长。 相似文献
18.
以3年生红背型五唇兰组培苗为试验材料,分别用5%、10%、20%的PEG 6000溶液处理模拟干旱胁迫,研究不同程度的干旱对五唇兰光合系统的影响,结果表明：（1）干旱导致叶片的气孔密度、开度、长度逐渐降低,且随PEG胁迫时间的延长下降趋势越明显,处理15 d后PEG 10%以上处理与CK差异达显著水平。（2）干旱导致叶片中苹果酸含量逐渐降低,随着PEG处理时间的延长,五唇兰叶片的苹果酸含量下降趋势减缓,凌晨叶片的苹果酸含量显著高于傍晚,处理15 d后PEG 20%处理下傍晚的苹果酸含量差异达显著水平,与CK相比降低了27.16%。（3）干旱导致叶片的净光合速率、蒸腾速率、气孔导度逐渐降低,随PEG胁迫时间的延长下降越显著,胞间CO2浓度的变化趋势则相反,水分利用效率呈先升高后降低的趋势,处理后第15天PEG 5%以上处理与CK差异均达显著水平。（4）干旱导致五唇兰叶片叶绿素的初始荧光值（Fo）逐渐升高,可变荧光值（Fv）、最大荧光值（Fm）、PSⅡ实际光化学效率（Fv/Fm）、PS Ⅱ潜在光化学效率（Fv/Fo）则逐渐降低,表观电子传递速率（ETR）、光化学淬灭系数（qP）、PSⅡ实际光量子效率（Yield）随着PEG胁迫程度的增加而逐渐降低。非光化学淬灭系数（NPQ）随PEG胁迫浓度的增加显著提高,处理15 d后PEG 5%以上处理与CK差异达显著水平。结果表明,10%、20% PEG处理能够在较短时间内通过影响叶片的气孔关闭、降低气孔密度进而降低光合作用和阻碍光合代谢产物苹果酸的合成,同时影响五唇兰叶片对光能的吸收传递以及光化学转换,5% PEG处理在处理10 d后才表现出光合生理受到抑制的现象,说明中度、重度干旱能够在较短时间内影响五唇兰叶片的气孔性状,进而降低叶片的光合能力,导致光合产物的合成受阻,最终导致光合系统受到抑制。 相似文献