小麦叶片水分利用效率及相关生理性状的关系研究

利用19个抗旱性不同的小麦品种,对干旱状态下叶片水分利用效率和光合速率、蒸腾速率等12个指标之间的关系进行了研究。结果表明,叶片水分利用效率与叶片光合速率、蒸腾速率、气孔导度、胞间二氧化碳浓度、水势和叶片离体失水速率之间的关系密切,说明这些生理性状是瞬间和短时期叶片水分利用效率的直接影响因素;而与叶片抗氧化酶活性、蜡质含量、叶片湿度和相对含水量相关性不大。因此认为,应该有针对性地研究与水分利用效率关系密切的生理性状,为小麦抗旱节水遗传育种研究提供理论依据。     

冬小麦基因型离体叶片失水与产量结构和植株性状的关系

根据４年的研究结果，分析了在冬小麦基因型产量和株高变异较大时，离体叶片失水速率（ＲＷＬ）与产量构成和植株性状的关系，研究表明，ＲＷＬ基因型间存在显著差异。在多数情况下ＲＷＬ与产量和千粒重呈负相关，与株高呈正相关。研究还发现基因型位次随失水时间的变化，有低失水，先快后慢，先慢后快和高失水４种类型。ＲＷＬ与产量负相关随失水时间延长而减弱。基因型差异以失水２－３ｈ最为明显，且更具有较大生理意义，因此提出     

不同玉米杂交种及其亲本自交系抗旱性研究

以玉米杂交种及其亲本自交系为试验材料,对不同基因型玉米抗旱性进行了系统研究。结果表明：（1）在花期水分胁迫下,不同基因型玉米都表现出株高、单株叶面积、叶绿素等指标的下降,且下降的幅度不同。同时,水分胁迫下,玉米植物体内的生理代谢发生了明显变化。叶片相对含水量、保水能力显著降低,可溶性糖升高。与抗旱系数关联度密切的有：叶片相对含水量下降率、丙二醛伤害率、株高下降率等。（2）叶片相对含水量、叶水势即离体叶片失水速率与抗旱性关系密切。这些指标既可以反映植株受旱程度,又可以比较不同基因型玉米抗旱能力。（3）在花期水分胁迫下,不同基因型玉米产量都明显下降。抗旱性强的基因型下降的小,抗旱性弱的品种下降的多。可以用抗旱系数和抗旱指数来衡量不同基因型玉米的抗旱性。亲本及F1代间抗旱性在某些性状上有一定相关性。     

轻简化基质育苗棉苗栽前离床期耐受生理特性研究

【目的】明确棉花轻简化基质育苗技术下的幼苗离床耐受生理相关特性,为其安全存放和运输保护提供理论支持。【方法】设置了育苗基质添加保水剂和不添加保水剂的处理,以中棉所50为材料,研究了29 d苗龄的幼苗不同离床和复水条件下的相关生理指标变化。【结果】室内条件下棉苗离床的耐受过程中,幼苗叶片逐步失水,引起从叶片外部表层细胞结构到内部生理的一系列变化,最终影响移栽成活率。其中,离床3 d内是安全期,叶片含水量的损失不到5%,且及时复水后能达到幼苗离床前初始状态的98%以上,移栽成活率均在99%以上;此时叶片表层细胞结构相对完整,细胞连接相对平滑,保卫细胞相对饱满。离床5 d为临界期,此时复水仅能达到初期的93%左右;第5至7天叶片失水最快,这个阶段相对含水率日均下降15百分点;当失水降到50%以下(11 d后)时,叶片表层细胞皱缩较严重,细胞壁皱褶明显,气孔塌陷较深,复水后恢复能力弱。失水过程中真叶内脯氨酸、丙二醛含量和过氧化物酶活力随离床时间增加而上升/增加,过氧化氢酶和超氧化物歧化酶活力变化在前5 d上升,5 d后开始下降。【结论】保水剂有利于维持离床棉苗体内水分,缓解离床期干旱胁迫。     

不同黄秋葵种质对干旱的生理生化反应

以抗旱性不同的3个黄秋葵种质004-5、SLK-2和B015为试材,通过盆栽试验研究了结荚期水分胁迫下黄秋葵的一系列生理生化指标的变化,并探讨了这些指标与黄秋葵抗旱性之间的关系。结果表明：水分胁迫下,相对含水量和叶绿素含量下降;离体失水率、相对电导率、游离脯氨酸和可溶性蛋白质含量升高。这些指标在确定种质抗旱方面可以作为参考。     

两个玉米自交系苗期叶温的干旱响应研究

利用远红外热成像系统的技术,研究玉米自交系综3与87-1苗期叶片对干旱的响应以及生物量的积累变化。结果表明,在遭受中度干旱胁迫的条件下,87-1的相对生物鲜重(0.716)及相对生物干重(0.799)显著高于综3(0.564,0.658),87-1的叶温差(0.30℃)显著高于综3(0.13℃)。通过离体叶片分析,综3离体叶片较87-1失水速率快,叶温在离体短时间内下降更低。表明在响应水分胁迫方面,87-1较综3叶片蒸发量小,叶温变化大,保水能力好,87-1表现出了更强的耐旱性。生物量积累与叶温差存在紧密的相关性,较高叶温差的基因型在遭受到水分胁迫时生物量积累更强。     

转基因抗虫棉衡科棉369抗旱生理特性研究

以河北省当年棉花区试对照品种DP99B为对照,在足水和干旱两种条件下对衡科棉369抗旱性生理特性进行了研究,结果表明:衡科棉369离体叶片失水速率较低,在干旱胁迫下叶片含水量的变化较小。脯氨酸增加较多,超氧化物歧化酶(SOD)含量增加较多。说明衡科棉369比对照DP99B抗旱性强。     

棉花不同钾效率基因型对水分和低钾胁迫的响应研究

为探明不同钾效率棉花基因型在水分和低钾胁迫条件下的差异,采用盆栽试验,对2种基因型棉花一些生理生化指标及生物学产量的差异性进行研究。结果表明,棉花在逆境胁迫条件下,其生长状况及生理生化过程中发生一系列适应性改变,不同基因型、不同生育时期,其抗逆性也不同。表现为：不同处理条件下,棉花钾高效基因型(103)叶绿素含量指数高于棉花钾低效基因型(122),生物学产量也较高。同时103叶片丙二醛(MDA)含量低于122,表明103抗逆性较强。2种基因型间可溶性糖与脯氨酸(Pro)含量以及过氧化物酶(POD)活性变化一致,差异不显著。     

冬小麦气孔与非气孔失水特性的基因型差异

以三年的冬小麦区域试验参试品系为材料，测定分析了离体叶片失水速率（ＲＷＬ），叶片蒸腾速率（ＴＲ）和叶片初始含水量（ＩＷＣ），结果表明，ＲＷＬ，ＴＲ和ＩＷＣ都存在显著的基因型差异。品系间排序在不同次测定中有波动，但呈基本稳定的趋势。不同试验区同一天ＲＷＬ的测定结果综合可比性较好；年度间ＲＷＬ测定结果稳定，ＲＷＬ和ＩＷＣ趋向正态分布。ＲＷＬ和ＴＲ无相关关系，ＲＷＬ和ＩＷＣ有微弱的正相关趋势，三个性状与     

不同杂交稻灌浆期叶片衰老特性及其对水分亏缺的响应

为了探讨叶片衰老表现型,为水稻抗早衰栽培技术和抗早衰新品种选育提供依据,此文选用6个杂交稻组合,在抽穗后常规水分管理和限水条件下,研究根系活力、叶片氮素含量、叶绿素含量、净光合速率、以及超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性动态及其对水分亏缺的响应。结果表明,不同组合的根系伤流强度、叶片氮素含量、叶绿素含量和净光合速率的衰减节律有明显差异,表现在衰减的起始时间、频率和衰减量。不同组合各生理指标对水分亏缺的响应不完全一致。叶绿素含量衰减率与根系活力和叶片氮含量衰减率呈极显著正相关关系;净光合速率与叶绿素含量呈极显著正相关关系。SOD、CAT和POD活性动态不同,不同组合对水分亏缺的响应不同。叶绿素含量、叶片氮素含量的变化动态与SOD和CAT活性呈极显著正相关关系;叶绿素含量、叶片氮素含量的变化动态与丙二醛（MDA）含量呈极显著负相关关系。不同杂交稻组合叶片生理指标的衰减节律及其对水分亏缺响应存在基因型差异;提高根系活力和叶片抗氧化保护酶活性,利于延缓叶片氮素含量和叶绿素含量的衰减、维持叶片较高的光合功能。水稻的抗衰老特性是基因型差异及其各项生理机能对环境应答结果。     

花后干旱和渍水对冬小麦光合特性和物质运转的影响

在温室盆栽条件下，以黑小麦76、皖麦38、扬麦10号、扬麦9号4个蛋白质含量不同的冬小麦(Triticum aestivum L.) 基因型为材料，研究了花后土壤干旱（Soil relative water content, SRWC=45%～50%）、渍水和适宜水分条件（SRWC=75%～80%）下，小麦旗叶净光合速率和叶绿素含量的动态变化，营养器官花前贮藏同化物再运转，花后同     

Relationships between leaf morpho‐anatomy,water status and cell membrane stability in leaves of wheat seedlings subjected to severe soil drought

The impact of the genotype‐specific leaf morphological and anatomical characteristics on the ability of wheat plants to preserve leaf water balance and cell membranes stability under drought stress was investigated. Seedlings of six modern semi‐dwarf (carriers of Rht, Reduced height genes) and six old tall bread wheat varieties were subjected to soil drought by withholding watering for 6 days. Morpho‐anatomical traits (leaf area, perimeter, thickness, stomata and trichome density) of daily watered (control) plants were characterized by light microscopy, scanning and image analyses. The leaf water status in both control and stressed plants was determined by measuring the relative water content (RWC). The leaf cell membranes stability in stressed plants was estimated by conductometric determination of the membranes injury index. On average, the modern semi‐dwarf varieties had less leaf area and leaf perimeter, and less dissection index, a parameter characterizing the leaf shape. Under drought stress, the modern genotypes maintained better water balance evidenced by significantly higher leaf RWC and better‐preserved the cell membranes stability supported by significantly lower Injury index. The correlations between morpho‐anatomical traits in control plants and drought tolerance‐related traits showed that the higher the leaf dissection index (i.e. more oblong leaves), the greater the water loss and the leaf membrane damages after desiccation were. The effect of shape of the evaporating surface on the water loss was modelled using wet filter paper. Similar to plant leaves, the evaporation and, respectively, water loss from paper pieces of more oblong shape (i.e. higher dissection index) was more intensive. The elucidation of the impact of the leaf shape on transpiration might contribute to better understanding of the mechanisms used by plants to maintain water reserves during drought stress and could be a basis for developing of simple and fast screening methods aiding the selection of drought tolerant genotypes.     

Ability of chromosome 4H to compensate for 4D in response to drought stress in a newly developed and identified wheat–barley 4H(4D) disomic substitution line

A spontaneously developed wheat–barley 4H(4D) disomic substitution line was identified cytogenetically using genomic in situ hybridization (GISH), multicolour fluorescent in situ hybridization (FISH) and microsatellite markers. The ability of the barley 4H chromosome to compensate for wheat 4D in response to mild drought stress was also investigated. In the barley cv. 'Betzes' and the 4H(4D) substitution line, mild osmotic stress induced intensive stomatal closure, resulting in reduced water loss through transpiration and unchanged relative water content in the leaves. As the CO₂ assimilation rate remained relatively high, the water use efficiency, which is an important factor associated with drought tolerance, increased extensively under mild osmotic stress in these lines. In the case of the parental wheat genotypes, however, mild drought stress induced less intense stomatal closure and a greater decrease in the CO₂ assimilation rate than in barley or in the substitution line, resulting in unaugmented or reduced water use efficiency. The results demonstrate that genes localised on the 4H chromosome of barley were able to increase the water use efficiency of the wheat substitution line, which is suitable for improving wheat drought tolerance through intergeneric crossing.     

施肥对旱作冬小麦植株水分变化与光合生理特性的影响

研究表明，中等以上肥力的冬小麦水浇地改为旱作时，通过合理施用有机肥和氮素化肥，可使土壤保持较高的含水量。随着有机肥用量的增加，植株叶片气孔导度变小，蒸腾速率与光合速率下降，叶片保水能力增强，提高了小麦植株的光合作用效率。与施用化肥相比，有机肥在降低植株叶片相对含水量、脱水速率方面作用显著。这些生理特性的改善，导致小麦产量提高１１％，从而达到充分利用当地自然降水，节约地下水，降低生产成本，获得与水浇     

小麦灌浆期上三叶叶绿素含量与产量和品质的关系

为了探讨灌浆期小麦上三叶叶绿素含量与产量和品质性状之间的关系,以49个基因型为参试材料,对上三叶叶绿素含量、穗粒数、千粒重、穗粒重、蛋白质含量和湿面筋含量进行测定。结果表明：基因型间、上三叶间、不同灌浆期间叶绿素含量均存在较大差异,基因型间穗粒数、千粒重、穗粒重、蛋白质含量和湿面筋含量也存在较大差异;上三叶叶绿素含量与穗粒数、千粒重、穗粒重、蛋白质含量和湿面筋含量均呈正相关关系,其中5月10日倒三叶、5月15日倒二叶和倒三叶、5月19日倒二叶和倒三叶与穗粒数达到显著或极显著相关,5月19日旗叶和倒二叶和5月24日上三叶（旗叶、倒二叶和倒三叶）与千粒重均达显著或极显著相关,5月10日倒三叶、5月15日倒二叶和倒三叶、5月19日上三叶（旗叶、倒二叶和倒三叶）和5月24日旗叶和倒二叶与穗粒重相关性均达显著或极显著水平,除5月10日旗叶外其他叶绿素含量与蛋白质含量和湿面筋含量均达显著或极显著水平。灌浆期上三叶叶绿素含量对产量和品质性状有重要影响。     

Comparative osmotic adjustments in barley and tetraploid wheats

Five barley (Hordeum rulgare L.), five durum wheat (Triticum turgidum concar. durum L.) and one wild emmer wheat (Triticum turgidum conrar dicoccoides) genotypes from different origins and differing for drought tolerance and potential yield, were studied for their osmotic adjustment capacity at the same stage and under similar water stress conditions. Differences for water status parameters between barley and tetraploid wheat genotypes were noted and discussed. The lowest osmotic adjustment capacities were noted in drought susceptible varieties, while a high capacity was found in genotypes exhibiting a high yield stability across contrasting environments. Relative water content, leaf osmotic potential and accumulation of soluble sugars were found to be highly related with osmotic adjustment: they could be used as criteria for a rapid evaluation of osmotic adjustment in segregating populations.     

用冠层反射光谱预测小麦叶片糖氮量及糖氮比

在不同土壤水氮条件下,研究了小麦中后期叶片碳氮状况及其比例与冠层光谱反射特征的关系。结果表明,叶片可溶性糖含量和积累量均随比值指数R(660, 460)的增加而降低,呈极显著负指数相关,而与其他植被指数相关不显著;叶片氮含量和氮积累量分别与比值指数R(950, 710)和R(950, 560)呈极显著正直线相关。发现小麦叶片糖氮比     

变水处理条件下小麦幼苗的甜菜碱代谢与抗旱性的关系

在缓慢土壤水分胁迫一复水的变水处理条件下,小麦幼苗地上部分相对含水量在80%~70%时,甜菜碱含量及甜菜碱醛脱氢酶活性最高,相对含水量大于80%或小于70%,甜菜碱的含量和甜菜碱醛脱氢酶活性都降低,并且两者变化是“同步”的。水分胁迫时,小麦幼苗迅速积累甜菜碱,抗旱型小麦增加6~8倍,水分敏感型增加4倍。积累甜菜碱与     

Differential Responses of Antioxidative Defence System to Long‐Term Field Drought in Wheat (Triticum aestivum L.) Genotypes Differing in Drought Tolerance

Drought is a severe abiotic stress and the major constraint on wheat (Triticum aestivum L.) productivity world wide. Deciphering the mechanisms of drought tolerance is a challenging task because of the complexity of drought responses, environmental factors and their interactions. The objective of this study was to evaluate the ability of the antioxidative defence system in imparting tolerance against drought‐induced oxidative stress and yield loss in two wheat genotypes, when subjected to long‐term field drought. Drought resulted in an increase in H₂O₂ accumulation and lipid peroxidation and decrease in ascorbate level in roots and leaves at different plant developmental stages. Drought‐tolerant genotype having higher antioxidative enzymes activities, and ascorbate level was superior to that of sensitive genotype in maintaining lower H₂O₂ content and lipid peroxidation and higher growth, yield and yield components under water deficit. Various antioxidative enzymes showed positive correlation with ascorbate and negative with H₂O₂ content. In developing grains, antioxidative defence response was nearly similar among both the genotypes under control condition; however, sensitive genotype failed to modulate the activities of antioxidative enzymes according to the ROS rush under field drought. Poor capacity of the antioxidative defence system in vegetative and reproductive tissues of sensitive genotype seems to be responsible, at least partly, for reduced yield potential under water deficit.