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1.
干旱和盐胁迫对棉苗光合抑制效应的比较 总被引：11，自引：7，他引：11
以无盐正常供水为对照,研究了等渗条件下干旱和NaCl处理对棉苗光合速率(Pn)、叶绿素荧光参数、过氧化物酶(POD)活性和丙二醛(MAD)与游离脯氨酸(Pro)含量的影响.干旱和盐胁迫都显著降低叶片的Pn、蒸腾速率(Tr)、气孔导度(Gs)、气孔限制值(Ls)和叶绿素与类胡罗卜素含量.干旱或盐胁迫引起初始荧光(F0)上升,最大荧光(Fm)、PSⅡ原初光能转化效率(Fv/Fm)和PSⅡ潜在活性(Fv/F0)显著下降,PSⅡ实际光化学量子产量(φPSⅡ)略有降低,而POD活性、MDA和Pro含量显著提高.棉苗在不同胁迫后的叶绿素含量、POD活性、MDA和Pro累积等方面存在量上的差异,说明等渗条件下干旱和盐胁迫对光合的抑制效应与机理存在诸多相似性,也有特异性. 相似文献
2.
干旱胁迫对玉米叶绿素荧光参数及质膜透性的影响 总被引：5，自引：0，他引：5
以抗旱性不同的3个玉米品种京单28、郑单958、京科25为试材,研究干旱胁迫下玉米的叶绿素荧光参数及质膜透性的变化.结果表明:干旱胁迫对叶绿素荧光参数的影响非常显著,干旱胁迫会降低玉米PSⅡ的原初光能转化效率(Fv/Fm),使PSⅡ反应中心开放部分比例(qP)降低,用于光合作用电子传递的份额(qP)减少,而以热能的形式耗散,过量的光能不及时耗散会使光合器官受到损伤,导致玉米叶片原生质膜结构伤害,从而引起膜的透性增大,玉米叶片中丙二醛、脯氨酸含量变化. 相似文献
3.
叔胺类活物质对玉米叶片光合特性与叶绿素荧光特性的调控效应 总被引：9，自引：2，他引：7
以玉米农大108为试验材料,在温室和盆栽条件下,研究叶面喷施叔胺类活物质DCPTA和DTA-6对玉米苗期叶片光合特性、光合关键酶以及叶绿素荧光特性的调控机制。结果表明,DCPTA和DTA-6处理显著提高了玉米株高和生物量;显著提高了玉米叶片光合速率、蒸腾速率、气孔导度和叶绿素含量,降低了细胞间隙CO2浓度,但不改变叶绿素a/b值;显著提高了PEPC羧化酶和RuBP羧化酶活性;显著提高了玉米叶片PSⅡ最大光化学效率(Fv/Fm)、PSⅡ有效电子产量(ΦPSⅡ)和光化学淬灭(qP),降低了非光化学淬灭系数qN;DCPTA和DTA-6处理的适宜浓度分别为50和20 mg/L。 相似文献
4.
C3、C4植物叶片叶绿素荧光猝灭日变化和对光氧化作用的响应 总被引：21，自引：0，他引：21
C3植物花生和C4植物甘蔗的光合色素含量、△A505nm、叶绿素荧光参数Fv/Fm, ΦPS Ⅱ,qN和qp呈日变化进程。中午前后,甘蔗的qN, qp, Fv/Fm和ΦPS Ⅱ的变幅比花生小,△A505nm的增值比花生大,叶绿素和类胡萝卜素仍维持较高水平,而此时花生的qN和qp皆下降。花生和苋菜(C4植物)经甲基紫精(MV)的光氧化处理后,叶片的MDA和蛋白 相似文献
5.
DCPTA对低温胁迫下玉米幼苗叶片叶绿素含量及其荧光特性的影响 总被引：6，自引：2，他引：4
以郑单958为盆栽试验材料,设置3个昼夜温度梯度(18℃/9℃、16℃/7℃、14℃/5℃),研究喷施不同浓度DCPTA对玉米幼苗叶片的叶绿素含量以及叶绿素荧光特性的调控机制。结果表明,低温胁迫下喷施DCPTA玉米幼苗的叶绿素含量比对照(清水处理)高23.62%~144.55%;玉米叶片Fo(初始荧光)比对照低4.55%~39.53%,Fv/Fo(PSⅡ潜在活性)、Fv/Fm(PSⅡ最大光化学效率)、qN(非光化学猝灭系数)分别比对照高出30.26%~112.39%、7.47%~32.96%、5.98%~57.52%;浓度为50mg/L的DCPTA喷施玉米幼苗叶片后,对低温胁迫下玉米叶片光合系统的保护效果最好,这有利于提高玉米幼苗叶片的抗冷性。 相似文献
6.
持续干旱对油棕幼苗叶绿素荧光动力学参数的影响 总被引：2，自引：2，他引：0
为研究持续干旱对油棕叶绿素荧光动力学参数的影响,以油棕2 年生幼苗为试验材料,采用盆栽方式模拟自然持续干旱,测定叶绿素荧光参数及叶绿素含量,并运用隶属函数法对其抗旱性进行综合分析。结果表明：干旱胁迫下,油棕叶片叶绿素含量、可变荧光(Fv)、最大荧光(Fm)、可变荧光与最大荧光比(Fv/Fm)均降低;初始荧光(F0)和非光化学淬灭系数(NPQ)则升高,说明干旱胁迫伤害了光系统Ⅱ(PSⅡ),使得PSⅡ原初光能转换效率(Fv/Fm)降低,光合电子传递、光合原初反应过程受到抑制,起光保护作用的热耗散(NPQ)提高。4 个品种的叶绿素荧光参数和叶绿素含量的变化存在品种间差异,整个处理过中对干旱的适应性‘热油6号’＞‘热油8号’＞‘热油2号’＞‘热油4号’,因此,叶绿素荧光参数和叶绿素含量可作为抗旱性强弱的诊断指标用于油棕抗旱育种及相关研究。 相似文献
7.
花后水分亏缺对玉米叶绿素荧光动力学参数及产量的影响 总被引：3，自引：0，他引：3
为了研究玉米农艺补偿技术,在旱棚控制条件下模拟土壤水分亏缺,研究花后不同阶段及不同程度水分亏缺对玉米叶绿素荧光动力学参数以及玉米产量的影响。结果表明:花后不同水分亏缺对叶绿素荧光动力学参数的影响不同,吐丝15 d时玉米穗位叶的PSⅡ潜在活性和Fv/Fm均大于吐丝45 d;随着水分亏缺时间的延长,PSⅡ潜在活性、Fv/Fm和qP值逐渐下降,而qN值逐渐上升,不利于光能的转化,导致产量降低。而短期胁迫后对荧光影响不明显,玉米穗位叶光合能力下降不显著。花后不同阶段水分亏缺对玉米产量的影响不同,灌浆中期至成熟期水分亏缺(T3)全生育期水分正常供应(T1)吐丝期至灌浆中期水分亏缺(T2)吐丝期至成熟期水分亏缺(T4)。T3的产量比T1增加3.5%,这是由千粒重增加所引起的,T2产量减少主要是由于穗粒数减少了3.9%,T4处理使穗粒数和千粒重都显著减少,从而使产量降低19.7%。 相似文献
8.
为探讨弱光胁迫下谷子光合生理响应,以衡谷13号为材料,在幼苗期设置7种不同遮光处理（遮光0、10%、20%、30%、40%、50%、70%）,在拔节期和灌浆期测定叶绿素含量、叶面积、净光合速率、产量和快速叶绿素荧光动力学参数的变化。结果表明,谷子叶绿素含量、叶面积、净光合速率、产量在遮光率高于20%时开始下降。荧光参数暗适应后初始荧光（Fo）、最大荧光（Fm）和可变荧光（Fv）在遮光后增大,PSⅡ反应中心最大光能转换率（Fv/Fm）、PSⅡ反应中心潜在活性（Fv/Fo）、光合性能指数（Pi_Abs）先随着遮光率的增大逐渐上升,遮光率为30%时达到最高,之后下降,遮光率为70%时低于对照。非光化学淬灭系数（NPQ_Lss）随着遮光程度的增大逐渐降低。 相似文献
9.
干旱胁迫下外源油菜素内酯对玉米幼苗光合作用和D1蛋白的调控效应 总被引：1，自引：0，他引：1
为了揭示干旱胁迫下外源油菜素内酯对玉米幼苗光合作用的保护机制,采用溶液培养的方法,以驻玉309为试验材料,研究外源油菜素内酯(BR)预处理及20% PEG-6000模拟干旱胁迫后玉米幼苗的生长参数、叶绿素含量、光合参数、叶绿素荧光参数及D1蛋白含量的变化。结果表明,与干旱胁迫处理(PEG)相比,BR+PEG处理的玉米苗株高增加45.87%,根长增加20.56%,总干物质积累增加8.01%,叶片相对含水量提高4.50%,叶绿素a含量增加26.32%,光合参数(Pn、Gs、Ci、Tr)分别提高9.57%,38.23%,30.19%,28.12%,光合系统Ⅱ(ΦPSⅡ)活性提高了20.48%,最大光化学效率提高了0.66%,光合系统Ⅱ绝对电子传递速率(ETR(Ⅱ)和相对电子传递速率r ETR(Ⅱ))分别提高20.40%和31.02%;D1蛋白含量增加37.34%(P0.05)。说明在干旱胁迫条件下叶片喷施BR可以改善玉米幼苗的生长发育,减缓光合系统的损伤,促进D1蛋白质的稳定,从而提高玉米幼苗对干旱胁迫的适应性。 相似文献
10.
11.
玉米和小麦在光合诱导期间非光化学猝灭（qN）差异 总被引：1，自引：0，他引：1
为了比较玉米(Zea mays L.)（C4）与小麦 (Triticum aestivum L.)（C3）黑暗向光照变化过程中的光诱导适应性反应，对非光化学猝灭（Non-photochemical quenching, qN）的动态变化特征进行了观察和分析。结果表明，在15 min至24 h的不同暗适应处理中，根据qN的光适应的动态变化可分为F型（快速稳定型）、M型（中速稳定型）和S型（慢速稳定型）3种。在暗适应后的光诱导期间，小麦qN主要表现出M和F型，玉米则表现出S和M型。通过对主要的荧光参数分析，小麦与玉米的Fv/Fm,qp和ΦpsII差异较小，而且qN稳定值有一定的差异，但TqNmex(qN达到最大值的时间）和TqN（qN达到稳定值的时间）玉米明显高于小麦，差异极明显。进一步分析经黑暗处理后光诱导的光合速率和气孔导度的动态变化，两作物虽然在增加的速率和稳定后的绝对值有差异，但达到稳定的时间无明显的不同。通过塑料膜包封叶片的方法阴止CO2同化，而qN变化特征也基本不改变。这意味着短时间的C代谢不明显影响qN对光诱导的反应。对光系统I反应中心P703的典型氧化还原方式的测定和电子库容能力的分析也表明它们不是造成qN动态变化的主要原因。然而，对qNmex成分的分析证明高能态猝灭（high-energy state quenching,qE）、转化猝灭（transition quenching,qT)和光抑制猝灭（photoinhibitory quenching,q1)分别为55.6%、18.5%和25.9%，说明qE是导致玉米qN在暗处理后的光诱导表现出TqNmex高、TqN长的主要原因。这意味着玉米（C4）在暗一光的变化中维持较高的qE，保持较高的类囊体质子梯度，有益于启动NADPH和ATP的形成。 相似文献
12.
为比较抗寒性不同的冬麦品种低温和不同光强作用下叶绿素荧光参数的变化,以3个抗寒性不同的冬麦品种为材料,分别在低温驯化期、低温驯化结束期和封冻期取样,室内暗处理后给予6个不同的光强,测定不同光强下的光合电子传递速率(ETR)、光化学猝灭系数(qP)和非光化学猝灭系数(qN)。结果表明,低温、高光强下抗寒品种东农冬麦1号的ETR、qP和qN显著高于其他2个品种,济麦22的这几个叶绿素荧光参数最低。封冻前抗寒中间型东农705品系的热耗散保持较高水平,但进入封冻期后其热耗散能力迅速降低。 相似文献
13.
Eight sweet potato cultivars ( Ipomoea batatas Lam.) were grown under four different light regimes (0, 26, 42 and 60 % light reduction (LR)) at two experimental sites of the International Potato Center (CIP) in Peru during the 1990 and 1991 growing season. Increasing shade diminished the tuber yield of five cultivars, two showed a tolerance for slight (26 % LR) and moderate (42 % LR) shade and one had the same yield in full sunshine and slight shade. Shade mainly reduced the sink-size (tubers m −2 ) of sweet potato and to a lesser extent the sink-strength. The growth of the plant top was hardly affected by shade; slight shade even favoured shoot development of some cultivars. The plant top was the stronger sink under shade conditions and tuber yield was not only reduced by lesser assimilate production as a whole but also by an altered assimilate partitioning. 相似文献
14.
M. Guadalupe Arenas‐Corraliza M. Lourdes Lpez‐Díaz Víctor Rolo Gerardo Moreno 《Journal of Agronomy and Crop Science》2021,207(1):100-119
Agroforestry systems are reported as climate‐resilient productive systems, but it is yet unclear how tree shade affects crops performance. The aim of this work was to assess how the phenology, plant traits and grain yield of wheat and barley were affected by shade. In an open greenhouse experiment, we cultivated in pots nine cultivars differing in precocity for each species and imposed three artificial shading levels (S0 ~ 0%, S1 ~ 25%, S2 ~ 50%) at the start of cereal booting. Our results showed that shade speeded up first growth stages in both species, until the starting of milk development. Barley showed consistent phenological responses to the three irradiance levels among cultivars, but not wheat that showed larger phenological differences among cultivars at moderate shade. Deep shade prolonged the time needed for wheat grain ripening. Both species increased grain yield by 15%–20% with shade, driven by shade‐acclimations of plant traits that differed among species. For wheat, grain yield was determined by the assemblage of traits that contribute to yield, such as grain weight, precocity and non‐photochemical quenching, while, for barley, SPAD value, precocity to reach phenological stages, grains per spike and plant height had the strongest influence. These traits varied widely among cultivars and seem of interest to identify best suited cultivars for shading conditions of Mediterranean agroforestry systems. 相似文献
15.
In every agroforestry system, the tree canopy reduces the incident radiation for the crop. However, cereal varieties were selected, and most crop growth models were designed for unshaded conditions, so both may be unsuited to agroforestry conditions and performance. In southern France, durum wheat productivity was monitored over 2 years in an agroforestry system including walnut trees and under artificial shade conditions. Yield components were measured in both full and reduced light conditions. The cereal yield was always decreased by shade; by almost 50% for the heaviest shade conditions (31% of light reduction). The main effect of the shade was the reduction in the number of grains per spike (35% at the most) and in the weight of grains (16% at the most). The mean grain weight was moderately affected, while the protein content was increased in shaded conditions (by up to 38% for artificial shade). Consequently, the protein yield per hectare was less reduced by the shade than the dry matter grain yield. A crop model (STICS) was also used to simulate the crop productivity in full light and shaded conditions, but the crop LAI and the yield components were not correctly simulated in the shade. The simulations emphasized the sensitivity of the wheat grain filling to shade during the critical period, 30 days before flowering, for yield elaboration. Further experimental and modelling studies should take into account the heterogeneity of shade intensity due to the shape of the tree crown, the width of the crop alley and the orientation of the tree rows and the modification of carbon allocation inside the plant. 相似文献
16.
The Effect of Different Shade Levels on Growth and Tuber Yield of Sweet Potato: I. Plant Development
The plant development of three sweet potato cultivars under different shade levels was compared during the 1990 and 1991 growth season at two locations in Peru. Deep shade retarded the time of tuber initiation of two cultivars. All shade levels reduced the number of tuber/m2 , hence the sink-size. After the 13th week after planting (WaP) the yield increased very rapidly in full sunlight. Shade reduced these growth rates and the highest increases occurred later in the vegetative period. Therefore, shade generally affected the tuber initiation and formation and eventually tuber yield.
Shoot growth terminated 13 WaP; only in deep shade did the plant top keep growing until harvest and competed permanently for assimilates with the tuber-sink. The leaf area was hardly affected by shade. The leaf area ratio increased in shade and there was a negative correlation between LAR and tuber and biomass yield. Shade also augmented the specific leaf area by approximately 11 % in 26 % and 42 % light reduction (LR) and up to 20 % in 60 % LR. 相似文献
Shoot growth terminated 13 WaP; only in deep shade did the plant top keep growing until harvest and competed permanently for assimilates with the tuber-sink. The leaf area was hardly affected by shade. The leaf area ratio increased in shade and there was a negative correlation between LAR and tuber and biomass yield. Shade also augmented the specific leaf area by approximately 11 % in 26 % and 42 % light reduction (LR) and up to 20 % in 60 % LR. 相似文献
17.
北疆棉花不同品种叶绿素荧光特性的研究 总被引：8，自引：3，他引：5
测定了北疆6个不同棉花品种田间叶片的净光合作用、荧光参数的变化。结果表明:晴天棉花叶片的光化学效率(Fv/Fm)随着光强上升而下降,到14∶00左右降到最低值,之后又随光强的减弱逐渐回升;非光化学猝灭系数(qN)则与此相反。棉叶在晴天易发生光抑制,可能会引发反应中心的降解等破坏反应。产量较高的新陆早8号和新陆早10号的Fv/Fm、光化学猝灭系数(qP)均高,且正午过后Fv/Fm恢复较快,不仅能较强地吸收光能,同时还具有较高的PSII的活性和光能转化效率,从而将所吸收的光能有效地转化为化学能,提高光合电子传递速度,形成更多的ATP和ENADPH,为光合碳同化提供充分的能量和还原能力。 相似文献
18.
Combining photovoltaic panels (PVPs) and crops on the same land unit were recently proposed as an alternative to the conversion of cropland into photovoltaic plants. This could alleviate the increasing competition for land between food and energy production. In such agrivoltaic systems, an upper layer of PVPs partially shades crops at ground level. The aim of this work was to (i) assess the effect on crop yield of two PVPs densities, resulting in two shade levels equal to 50% and 70% of the incoming radiation and (ii) identify morphological and physiological determinants of the plant response to shade. Experiments were conducted on four varieties of lettuces (two crisphead lettuces and two cutting lettuces), during two seasons. In all cases, the relative lettuce yield at harvest was equal or higher than the available relative radiation. Lettuce yield was maintained through an improved Radiation Interception Efficiency (RIE) in the shade, while Radiation Conversion Efficiency (RCE) did not change significantly. Enhanced RIE was explained by (i) an increase in the total leaf area per plant, despite a decrease in the number of leaves and (ii) a different distribution of leaf area among the pool of leaves, the maximal size of leaves increasing in the shade. Our result provides a framework for the selection of adapted varieties according to their morphological traits and physiological responses to PVP shade, in order to optimize agrivoltaic systems. 相似文献
19.
涝峪苔草叶绿素含量与耐阴性研究 总被引：6，自引：0，他引：6
为了探索不同光照条件下的涝峪苔草叶绿素含量与耐阴性的关系,通过对涝峪苔草及对照草地早熟禾在全光照及郁闭度为0.5、0.7、0.9林下的叶绿素含量、生长指标(叶片长度、叶片中部宽度、分蘖株数)进行研究。表明:在遮阴条件下,涝峪苔草及对照草地早熟禾叶绿素a、b含量及总叶绿素含量都比全光照条件下为大,但叶绿素a、b、a/b及总叶绿素含量增加快于对照草地早熟禾。叶色方面,遮阴后涝峪苔草叶色深绿,对照草地早熟禾为绿色。生长方面,在遮阴条件下涝峪苔草比对照草地早熟禾生长健壮,没有死亡现象。涝峪苔草能够在郁闭度为0.7￣0.9的强遮阴条件下正常生长,是中国北方地区园林绿化中良好的野生耐阴植物之一。 相似文献