干旱胁迫对山杏光合特性的影响

为筛选干旱地区生态建设的优良品种,以盆栽山杏为试材,控水模拟不同土壤水分状况,探讨了不同程度干旱胁迫对山杏叶片光合特性的影响.结果表明,山杏叶片净光合速率、蒸腾速率、气孔导度随着干旱胁迫程度的加强而降低.随着温度的升高,叶片净光合速率和水分利用效率降低、蒸腾速率升高,加重了干旱对其光合作用的影响.对照、轻度和中度干旱胁迫下的净光合速率、气孔导度及水分利用效率日变化曲线呈双峰型,重度胁迫下净光合速率和气孔导度日变化为单峰型.说明在一定的干旱条件下,山杏光合作用对干旱胁迫具有一定的适应能力.     

土壤水分胁迫对不同肥水类型冬小麦品种花后光合特性及产量的影响

为给小麦抗旱育种和节水高产栽培提供理论和技术支持,以山东省6个不同肥水类型的冬小麦品种（‘青麦6号’、‘鲁麦21’、‘烟农21’、‘烟农24’、‘济麦22’、‘良星99’）为材料,研究了水分胁迫对冬小麦花后光合特性与产量的影响及品种间差异。结果表明,在水分胁迫条件下,各冬小麦品种花后叶面积指数、旗叶叶绿素含量、净光合速率、气孔导度、蒸腾速率和水分利用效率均有所降低,产量显著下降。品种间对水分胁迫反应差异显著,其中旱地品种‘青麦6号’在水分胁迫条件下,旗叶叶绿素含量、净光合速率、蒸腾速率、水分利用效率及气孔导度均高于其他品种,产量构成因素和产量降低幅度最小,产量最高,仅比同期水分处理下降了14%。     

施肥对小麦叶片光合特性的影响

为了揭示肥料对小麦光合速率的影响效应,进而提高小麦的光合生产力,以小麦品种莱农0245为研究对象,对比分析了施肥和不施肥2种处理下,灌浆期旗叶的光合速率、蒸腾速率、气孔导度以及水分利用率对光强响应特征。结果表明:正常施肥时小麦的光合速率、蒸腾速率、气孔导度、水分利用率都随光强的增强而逐渐增大。不施肥条件下,蒸腾速率和气孔导度随光强的增强而逐渐增大,而在高光强(>1 200μmol/(m2.s))下,会产生光抑制现象,光合速率降低,这也造成水分利用率的降低。正常施肥条件下的光合速率、蒸腾速率、气孔导度均高于不施肥条件下。因此,适量施肥可以明显改善小麦的光合能力。     

渗透胁迫下不同玉米品种叶片水分关系的研究

通过盆栽及水培试验研究不同玉米品种在渗透胁下叶片的水分变化,结果表明：参试3个品种的气孔导度与光合速率、蒸腾速率均呈直线相关,但气孔导度对蒸腾速率的相关系数〉气孔导度对光合速率的相关系数;品种间气孔调节能力为农大60〉中单2号〉陕单911;陕单911的渗透调节能力〉中单2号〉农大60,陕单911能通过较低的渗透势和细胞内溶质含量的增加,维持细胞吸水,从而维持叶片较高的相对含水量和叶水势,并具有较高的膨压,维持细胞的延伸生长。3个品种的耐脱水干化能力不同,失水速度为陕单911〉农大60〉中单2号。     

水分胁迫对大丽花光合作用、蒸腾和气孔导度的影响

以大丽花品种‘粉西施’盆栽扦插苗为试材,研究了不同程度水分胁迫及复水对大丽花品种粉西施叶片光合作用、蒸腾和气孔导度的影响。结果表明：随着水分胁迫程度的加深和胁迫时间的延长,大丽花叶片的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和水分利用率(WUE)下降,胞间CO2浓度(Ci)先下降后上升,气孔限制值Ls先升高后下降。轻度和中度水分胁迫下,气孔限制是Pn降低的主要原因;重度水分胁迫下,非气孔限制是Pn降低的主要原因。重度胁迫更早对大丽花叶片造成伤害,重度胁迫下复水后光合指标难以恢复。     

土壤干旱对小麦叶片渗透调节和光合作用的影响

本文研究了土壤干旱对小麦叶片渗透调节和光合作用的影响.小麦叶片水势、相对含水量、饱和渗透势、光合速率、蒸腾速率和气孔导度随土壤干旱程度加剧呈现出先缓降后陡降的趋势,其变化的土壤相对含水量阈值相同.小麦旗叶的渗透调节能力约为0.5MPa,不同叶位叶片渗透调节能力不同,其强弱顺序为旗叶>倒二叶>倒三叶.干旱使叶片膨压丧失时的渗透势从正常水分处理的-1.61MPa降到-2.33MPa,弹性模量从5.74MPa增加到6.35MPa.干旱条件下的光合速率、气孔导度、气孔限制值和叶片光合放氧能力都下降,而细胞间隙CO_2含量增加,说明光合速率的降低是非气孔因素即叶肉细胞光合活性限制的结果.     

干旱胁迫对不同品种夏谷光合性能及水分利用率的影响

用盆栽控制浇水的方法对14个不同夏谷品种幼苗进行干旱处理,测定幼苗的净光合速率、蒸腾速率、气孔导度、胞间CO2浓度以及水分利用率.试验结果表明,在水分胁迫下,所有夏谷品种均表现为净光合速率下降、蒸腾速率降低、气孔导度降低,但胞间CO2浓度上升.与对照相比,干旱胁迫下夏谷的水分利用率均降低,但抗旱能力强的下降幅度较小.综合以上指标,可以初步认为:14个夏谷品种中,抗旱能力最强的是沧344、沧555、200152,济0404、郑06-3、冀谷19,200131、冀谷31、安06-6082、06716-7抗旱能力中等,安04-4783、206058、济0515、长生08抗旱能力较弱.     

腐殖酸水溶肥料对水分胁迫下小麦光合特性及产量的影响

为了解腐殖酸水溶肥料对水分胁迫下小麦光合特性及产量的影响。以‘永良四号’为试验材料,采用盆栽方法研究了拔节期水分胁迫后,腐殖酸水溶肥料对小麦叶绿素含量、光合速率、气孔导度、蒸腾速率及产量的影响。结果表明,在不同水分胁迫下,腐殖酸水溶肥料均有效地改善了小麦光合特性,与对照相比,叶绿素含量增加5.62%~84.32%,光合速率增加0.87%~75.38%,气孔导度降低7.96%~53.25%,蒸腾速率降低15.96%~58.32%。水分胁迫后,净光合速率和叶绿素含量下降。但在水分胁迫时喷施腐殖酸水溶肥料,叶绿素含量和净光合速率增加,蒸腾速率减弱,因而水分利用效率提高。小麦增产4.48%~7.75%,增产效果显著,增产幅度为：正常供水>适度控水>中度水分胁迫。综合分析表明,腐殖酸水溶肥料能改善小麦光合特性,增加其产量。     

棉花渗透调节与蒸腾速率的日变化关系

大田正常供水条件下，随１ｄ内光照和温度增加，棉花叶水势及渗透势下降，最低水势为－１１．４巴，渗透势为－１４．２巴，其膨压值为２．８巴，表现出渗透调节作用。气孔导度在中午一段时间最高，而蒸腾速率最高点在１２∶００时，之后下降，表明水分胁迫下产生渗透调节作用，使叶片保水力增加，蒸腾减弱。Ｋ＋和可溶性糖变化，以渗透势下降最低时积累最多，是棉花干旱时主要的渗透调节物质。     

干旱胁迫对金光杏梅叶片渗透调节物质和光合作用的影响

以金光杏梅盆栽幼苗为试材,研究了干旱胁迫对金光杏梅叶片渗透调节物质含量和光合作用日变化的影响.结果表明:随着干旱胁迫程度的增加,金光杏梅叶片相对含水量和叶绿素含量都明显降低;细胞质膜透性、丙二醛(MDA)、可溶性糖、脯氨酸(Pro)的含量显著增加;叶片净光合速率、蒸腾速率和气孔导度等都随着干旱胁迫的加重而降低,细胞间隙CO2浓度随着干旱胁迫的加重而升高;轻度干旱胁迫下,气孔限制是净光合速率降低的主要原因;严重干旱胁迫下,非气孔限制是净光合速率降低的主要原因.     

土壤水分胁迫对冬小麦叶片渗透调节及叶绿体超微结构的影响

土壤水分胁迫下 ,抗旱性强的小麦品种昌乐 5号、北农 2号与抗旱性弱的济南 13、鲁麦 5号相比 ,渗透调节能力高 0 4 1～ 0 60MPa ,相对含水量少降 6 39～ 10 74个百分点 ,叶水势少降 0 19～ 0 63MPa。水分胁迫使小麦叶片光合能力下降 ,水分胁迫全过程下降平均百分数 ,抗旱性强的品种比抗旱性弱的品种光合速率少降 17 7%～ 2 2 5% ;气孔导度少降 2 1 0 6%～2 3 75%。小麦叶肉细胞叶绿体的超微结构发生变化且随水分胁迫的加重而加剧 ,但变化程度与小麦的抗旱性及渗透调节能力成负相关。胁迫导致叶绿体外形变圆 ,类囊体肿胀 ,片层间距加大 ,基质片层模糊 ,最终叶绿体解体     

土壤水分胁迫下小麦叶片的渗透调节与膨压维持

两年的试验结果表明,在土壤缓慢脱水和长期水分胁迫下,四个小麦品种叶片均产生渗透调节,孕穗期和灌浆期渗透调节能力较强,渗透调节的幅度为0.40～0.64MPa,抗旱性强的品种大于抗旱性弱的品种.由于渗透调节在土壤含水量60%左右或轻度胁迫下,叶片膨压基本不变.五个生育期四个处理水平叶水势与膨压回归分析,从水势每下降一个单位,膨压降低的单位数看,昌乐5号(0.146)<山农587(0.151)<烟农15(0.162)<济南13(0.240),抗旱性强的品种由于渗透调节能力强,膨压降低的单位数小,维持膨压的程度高.     

Drought‐induced osmotic adjustment and changes in carbohydrate distribution in leaves and flowers of cotton (Gossypium hirsutum L.)

Research has indicated osmotic adjustment as a mechanism by which leaves and roots of cotton plants overcome a drought period. However, the relevance of this mechanism in reproductive tissues of modern cultivars under drought has not been fully investigated. The objectives of this study were to measure osmoregulation and carbohydrate balance in reproductive tissues and their subtending leaves grown under water‐deficit conditions. Two cotton cultivars were grown under controlled environment and field conditions. Plants were exposed to water‐deficit stress at peak flowering, approximately 70 days after planting. Measurements included stomatal conductance, proline concentration, soluble carbohydrates and starch concentration, and water potential components. Stomatal conductance of drought‐stressed plants was significantly lower compared to control, while osmotic adjustment occurred in reproductive tissues and their subtending leaves by different primary mechanisms. Pistils accumulated higher sucrose levels, maintaining cell turgor in plants exposed to drought at similar levels to those in well‐watered plants. However, subtending leaves lowered osmotic potential and maintained cell turgor by accumulating more proline. Soluble carbohydrates and starch concentration in leaves were more affected by drought than those of floral tissues, with corresponding reduction in dry matter, suggesting that flowers are more buffered from water‐deficit conditions than the adjacent leaves.     

石新733小麦的水分生理特点及节水灌溉效应

石新733是一个高产优质小麦新品种,为探明其是否适用于节水高产栽培,于2003—2004和2004—2005年度进行了节水灌溉对其水分生理性状和产量影响的田间试验。结果表明,石新733的叶片渗透调节能力比邯麦9、石麦9和衡7228的平均值高71.6%,叶水势比衡7228约高0.1 MPa。石新733的离体叶片失水速率较高;蒸腾速率、净光合速率和气孔导度与石麦9和邯麦9接近,均高于衡7228;胞间CO₂浓度和蒸腾效率品种间没有明显差别。与灌5水处理相比,灌2水处理的叶水势和叶片气体交换参数均相近而灌浆盛期的光合功能和蒸腾效率较高。石新733的产量高于其他3个品种,其中,不灌水和灌2水处理分别比其他3个品种平均产量增加11.3%和7.0%。全生育期只灌拔节和抽穗开花期2水的节水处理比灌4水的常规灌溉处理增产5.6%,说明该品种可在节水高产栽培上应用。     

冬小麦抗旱生理特性的研究

试验结果表明，干旱胁迫下抗旱性不同的冬小麦品种的抗旱系数为：昌乐5号＞秦麦3号＞山农587＞济南13＞鲁麦5号＞烟农15。五个生育期的叶片渗透调节能力为抗旱性强的品种大于抗旱性弱的品种，抗旱系数和渗透调节能力是反映冬小麦抗旱特性的两个最好指标。拔节、孕穗和开花期抗旱性强的品种气孔阻力比抗旱性弱的品种大，灌浆和     

Water Stress and Potassium Fertilization in Field Grown Maize (Zea mays L.): Effects on Leaf Water Relations and Leaf Rolling

Three cultivars of maize ( Zea mays L.) were grown in the experimental field at Hiroshima University, Japan under two levels of K fertilization with a non-irrigated water stress treatment and an irrigated control during June to August 1990. Leaf water potential, osmotic potential and stomatal conductance were measured 21 d after withholding water. Diurnal changes in degree of leaf rolling were measured on the 22nd day after withholding water. Leaf water potential and osmotic potential at full turgor were lower in the non-irrigated plants than irrigated and they were lower in the high K plants than the low K plants. Lowering of osmotic potential (osmotic adjustment) helped to maintain turgor under low water potential conditions. Turgor potential was increased by the higher K fertilization. Higher turgor potential may contribute to the higher stomatal conductance observed in non-irrigated high K plants. The degree of leaf rolling increased towards noon, and it was lower in high K plants than in low K plants. High K plants recovered from leaf rolling faster than the low K plants during the afternoon. High K. plants could maintain higher turgor potential throughout the day than the low K plants. Degree of leaf rolling was the lowest in the cultivar K-8388 which maintained the highest turgor potential via osmotic adjustment and it recovered from leaf rolling faster than the other two cultivars. Higher levels of K fertilization may be beneficial for maize plants to tolerate to water stress conditions.     

干旱对大豆生理及产量影响的研究

干旱对农业生产影响巨大,开展干旱胁迫对大豆生理及产量影响的研究,将为干旱地区大豆生产提供理论依据。利用塑料整理箱进行了干旱胁迫对大豆光合生理、叶片抗氧化物酶和渗透调节物以及生物量、产量影响的研究,土壤水分为干旱(45%~55%的田间土壤最大持水量)和湿润(80%~100%的田间土壤最大持水量,CK)2个水平,进行了2年的试验研究。结果表明,干旱胁迫使大豆净光合速率、气孔导度、蒸腾速率均明显下降,使水分利用率增加;干旱胁迫对大豆叶片过氧化酶(POD)和超氧化物歧化酶(SOD)含量无显著影响;干旱使大豆叶片丙二醛(MDA)含量、还原糖含量和可溶性总糖含量增加25.00%,47.09%和47.16%。干旱胁迫使大豆株高、节数、茎粗明显下降。干旱使大豆地上部分生物量明显下降,其中2013年下降39.4%,2014年下降69.6%。干旱使大豆籽粒产量明显下降,2013,2014年分别下降46.9%和81.6%。干旱胁迫下,大豆叶片气孔导度显著下降,使CO2供应受到严重影响,降低叶片净光合速率。干旱胁迫还会使大豆细胞膜结构造成一定的破坏,影响植物正常的光合作用,使大豆光合代谢产物下降。虽然大豆可以通过渗透调节物质来保持细胞的水分,但干旱仍然抑制了植株的正常生长,使大豆生物量和产量下降。     

Atmospheric and soil water deficit induced changes in chemical and hydraulic signals in wheat (Triticum aestivum L.)

Plant responses to soil drying and the metabolic basis of drought-induced limitations in stomatal opening are still being discussed. In this study, we investigate the roles of root-born chemical and hydraulic signals on stomatal regulation in wheat genotypes as affected by soil drought and vapour pressure deficit. Twelve consecutive pot experiments were carried out in a glasshouse. Two bread wheat cultivars (Gönen and Basribey) were subjected to drought under high and low vapour pressure deficit (VPD) in a growth chamber. Total dry matter, specific leaf area, xylem ABA content, xylem osmotic potential, xylem pH, root water potential (RWP), stomatal conductance, leaf ABA content and photosynthetic activity were determined daily during 6 days after the onset of treatments (DAT). In the first phase of drought stress, soil drying induced an increase in the xylem ABA with a peak 3 DAT while RWP drastically decreased during the same period. Then the osmotic potential of leaves decreased and leaf ABA content increased 4 DAT. A similar peak was observed for stomatal conductance during the early stress phase, and it became stable and significantly higher than in well-watered conditions especially in high vapour deficit conditions (H-VPD). Furthermore, xylem pH and xylem osmotic potential appeared to be mostly associated with atmospheric moisture content than soil water availability. The results are discussed regarding possible drought adaptation of wheat under different atmospheric humidity.     

水分胁迫对水稻结实期一些生理性状的影响

选用抗旱性不同的3个杂交水稻品种，在干旱棚内分别在正常供水和水分胁迫条件下，研究了水稻结实期丙二醛（MDA）含量、光合速率、气孔导度、渗透调节物质及保护性酶活性等生理性状变化。结果表明，结实期随土壤水分胁迫加剧和时间延长细胞膜脂过氧化加剧，抗旱性弱的品种膜脂过氧化更为严重；剑叶光合速率、气孔导度和叶绿素含量迅速下降，抗旱性弱的品种比抗旱性强的品种降速快、幅度大。抽穗后0～14 d随胁迫时间的延长叶片内可溶性糖、氨基酸含量增加，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）3种酶活性升高，抗旱性强的品种增加或升高的幅度大。抽穗14 d后叶片内可溶性糖、氨基酸含量下降，SOD、CAT和POD酶活性降低。试验表明，水稻叶片MDA含量、光合作用、渗透调节物质及保护性酶活性的变化幅度与品种的抗旱性密切相关。