两种基因型玉米苞叶水势比较研究

以郑单958和农大364两个玉米品种为研究材料,对大田条件下玉米苞叶水势的变化规律进行了比较研究,并探讨了苞叶水势和饱和亏缺之间的关系.结果表明:两种基因型玉米苞叶水势日变化趋势基本一致,呈抛物线型;郑单958的苞叶水势日均值和日变幅高于农大364;苞叶水势和相对水分含量均随着玉米生育期推进呈现不断降低的趋势,饱和亏缺变化趋势与之相反;郑单958的苞叶饱和亏缺数值低于农大364,相对水分含量高于后者;苞叶水势和饱和亏缺之间呈线性关系:Y=A BX.郑单958常数项值比农大364大,表明在正常水分条件下郑单958饱和亏缺值较低,相对含水量较高,因此抗旱性强于农大364.     

高产冬小麦节水栽培的叶水势特征

田间和盆栽试验研究表明叶水势日变化曲线因供水和生育时期而不同，黎明前叶水势（ψ＾ｐｒｅ）开花期低谷十分明显，与土壤水分动态变化不一致，午后叶水势表现为前期低中期高后期渐降的变化特点，不同水文年型间存在差异，生育中后期叶水势与深层土壤水分含量的相关程度增强，开花期叶水势与产量关系最为密切。前期控水式的节水栽培在一定程度上降低生育期叶水势，可通过渗透调节功能和较高膨压的维持稳定高产。     

小麦“午睡”原因韵研究——Ⅱ.生理因子与“午睡”的关系

从叶水势、气孔开度和叶可溶性醣量日变化动态方面研究了大田小麦“午睡”的原因。认为:叶水势下降及其所引起的气孔开度减小是形成午睡的重要原因。叶水势降至-14巴,光合作用迅速下降,气孔开度急速变小;气孔开度减到2μm 以下则影响光合速率。中午叶可溶性醣过量积累则抑制光合作用,此亦“午睡”原因之一。     

小麦水分胁迫影响因子的定量研究Ⅰ.干旱和渍水胁迫对光合、蒸腾及干物质积累与分配的影响

通过冬小麦盆栽水分控制,研究了干旱和渍水胁迫下冬小麦水分生理生态关系。结果表明,存在凌晨叶水势临界值,当凌晨叶水势低于临界值后,植株叶片净光合速率显著降低,凌晨叶水势临界值可运用模糊聚类方法确定。在水分亏缺条件下,相对蒸腾速率和净光合速率随土壤水分变化的关系不相同,相对蒸腾速率与土壤相对含水量为直线     

水、旱栽培条件下水稻叶片水势与抗旱性的相关分析及其QTL定位

为了揭示叶片水势在水稻抗旱中所起的作用及其遗传机制, 以越富和IRAT109为亲本构建了120个重组自交系, 开展叶片水势与抗旱相关性及QTL定位的研究。重组自交系及亲本群体在旱田和水田两种条件下种植, 于始穗期测量叶片凌晨水势和中午水势; 以抗旱系数作为抗旱鉴定指标。结果表明, 叶片水势在重组自交系间变异显著。相关性分析表明旱田中午叶片水势与抗旱系数及旱田单株产量呈极显著正相关, 旱田叶片水势变化与抗旱系数及旱田单株产量呈极显著负相关, 说明旱田中午叶片水势高且能保持凌晨基础叶片水势的品种更具抗旱性。共检测到6个叶片水势加性QTL, 其中旱田凌晨叶片水势2个, 分别解释表型变异的5.4%和7.9%, 旱田中午叶片水势1个, 解释表型变异的10.0%, 旱田叶片水势变化2个, 分别解释表型变异的11.6%和9.5%, 水田叶片水势变化1个。未检测到水田叶片水势加性QTL。共检测到5对上位性效应QTL, 其中旱田中午和凌晨叶片水势各检测到1对上位性QTL, 水田凌晨叶片水势上位性QTL 1对, 水田中午叶片水势上位性QTL 2对。抗旱系数共检测到3个加性QTL和2对上位性QTL。叶片水势遗传力较低, 田间直观选择效果差, 利用分子标记辅助选择将会提高选择效率。     

高产冬小麦叶水势的变化特点与节水调控

１９８６－１９９０四个年度研究结果显示，叶水势是变化困供水及生育时期而不同。黎明前叶水势随生育进程而变化，开花期出现明显低谷，与土壤水分动态变化不一致；午后叶水势具有规律的阶段性变化，且因不同水文年型出现间差异。叶水势与土壤含水量呈曲线关系，随生育进程，叶水势与深层土壤水分的相关性增强。开花期叶水势与产量关系最为密切。前控式节水栽培可通过渗透调节维持较高膨压而高产。提出了不同水文年型高产节水主要生     

欧美杨(Populus nigra×P. deltoides)再生体系的建立

黑杨派（Aigeiros）的杂交后代欧美杨（Populus nigra × P. deltoides）在杨树叶锈病研究领域具有重要价值。本研究以叶柄、叶片和茎段作为外植体进行组织培养,构建欧美杨再生体系。分别优化了初代培养、继代培养、抽茎培养和生根培养的培养条件。正交试验结果表明最优初代培养培养基配方：MS 0.5 mg/L 6-BA 0.05 mg/L NAA。最优继代培养培养基配方：MS 0.5 mg/L 6-BA 0.1 mg/L NAA。最优抽茎培养培养基配方：MS 0.1 mg/L 6-BA 0.05 mg/L NAA。最优生根培养培养基配方：1/2MS 0.25 mg/L NAA 20 g/L蔗糖。以上培养基培养分别得到叶柄分化率为86.7%,不定芽诱导率为96.7%,抽茎率为91.7%,生根率为85%。再生苗移栽成活率为91.5%。所获得的欧美杨再生苗扩繁简便,可用于杨树抗叶锈病相关基因转化等研究。欧美杨再生体系为揭示欧美杨的感病机理提供物质基础。     

欧美杨溃疡病防治的初步研究

为探索防治欧美杨溃疡病的方法,采用平板稀释法,从欧美杨溃疡病病株的根际土壤中分离出86株细菌菌株。经平板对峙培养,得到5株对欧美杨溃疡病原菌(Lonsdalea quercina)有拮抗作用的菌株。室内离体枝条试验和田间杨树防治试验结果表明,以菌株P2和P4的防效较好,通过浇根处理,室外防效分别达到51.8%和48.6%。经鉴定菌株P2和P4分别为枯草芽孢杆菌Bacillus subtilis和委内瑞拉链霉菌Streptomyces venezuelae。用中生菌素、农用链霉素、新植霉素、多抗霉素等4种抗生素类药剂和45%代森铵水剂、80%乙蒜素乳油杀菌剂在室内做抑菌试验,中生菌素、新植霉素对病原菌无明显的抑制效果,其他4种有一定的抑制作用。其中农用链霉素100倍稀释液的防效较好,经浇根处理,室外防效达38.2%。试验为欧美杨溃疡病的防治提出了初步的方法。     

半根水分胁迫下苹果幼苗根系生长及水分状况研究

采用分根半根固定胁迫和半根交替胁迫的方法,研究了轻度（10%PEG）、中度（20% PEG）和重度（30%PEG）水分胁迫对平邑甜茶（Malus hupehensis）水培苗根系活力、根水势和叶片相对含水量的影响,结果表明：分根半根固定胁迫能有效地维持叶片含水量,增加未受胁迫半根的根干重、根表面积、根系活力和根水势,其保水效果优于分根半根交替胁迫处理。分根半根固定胁迫受水分胁迫的一半根（固干）的所有参数在整个胁迫过程中均显著高于全根受胁迫的根系;同时分根半根固定胁迫的叶片含水量和水势又高于交替分根胁迫的叶片含水量和水势,说明半根胁迫能在一定程度上发挥根系的高效吸水作用,提高叶水势,有利于植株保持良好的水分状况。     

包头市主要园林树种的耐旱性研究

共收集了包头市园林树种16种云衫、桧柏、侧柏、油松、榆叶梅等,通过叶水势的测定.依据模型,把测得的苗术叶水势与土壤含水量关系进行分析,结果表明包头市主要园林树种中属于高水势延迟脱水耐旱树种有油松、银老梅、黄刺梅、国槐、白蜡、杠柳;属于亚高水势延迟脱水耐旱树种有桧柏、榆叶梅、女贞、毛樱桃、珍珠梅、白榆、家杨、垂榆、山梅;属于低水势忍耐脱水耐旱树种有云衫、玫瑰;属于亚低水势忍耐脱水耐旱树种有侧柏、绣线菊、丁香、刺槐、旱柳.     

不同供水条件下小麦不同绿色器官的气孔特性研究

为了考察小麦叶片与非叶器官气孔结构特性的差异及其对供水条件的反应，本研究设置不同灌水处理，利用电镜观察小麦灌浆期不同绿色器官的气孔分布和结构特征，并分析其与气孔特性指标间的关系。结果表明，在不同灌水处理下看到各非叶器官（穗、旗叶鞘和穗下节间）均分布着气孔，但其数目少于旗叶叶片。护颖仅在远轴面存在气孔；外稃在多水条件下（4水处理）近轴面出现较多气孔，而远轴面看不到气孔，但在水分胁迫（无水处理）条件下，气孔却出现在远轴面而不在近轴面；在不同水分处理下均观察到芒上明显的气孔分布。从气孔大小看，穗各部分（护颖、外稃、内稃和芒）略小于其他器官。随着灌水次数的减少，各器官气孔密度呈增大趋势，气孔器及气孔孔径表现出长度增加、宽度减小的特征。限水灌溉下非叶器官（穗、旗叶鞘和穗下节间）在籽粒灌浆期气孔导度、蒸腾速率和光合速率的稳定性高于叶片。相关分析表明，不同器官的气孔导度与蒸腾速率均呈显著正相关，非叶器官气孔导度与光合速率的相关程度明显低于叶片。说明在干旱少水条件下，叶与非叶器官蒸腾作用均会减弱，叶片光合速率亦相应降低，而非叶器官光合速率可能保持相对稳定，可相对提高其水分利用效率。     

Sensitivity of Two Quinoa (ChenopodiumquinoaWilld.) Varieties to Progressive Drought Stress

Quinoa (ChenopodiumquinoaWilld.) is a highly nutritious Andean seed crop which shows great potential to grow under a range of hostile environments. The objective of this study was to investigate the differences of drought tolerance of a Bolivian (Achachino) and a Danish (Titicaca) variety, and especially drought‐related adaption strategies. Soil water status was expressed as the fraction of transpirable soil water (FTSW). Relative stomatal conductance (RSC), relative transpiration (RT) and relative leaf water potential (RLW) were calculated by determining stomatal conductance, transpiration rate and leaf water potential of the drought‐treated plants relative to those of fully irrigated plants. The responses of RSC, RT and RLW to decreasing FTSW were described by a linear‐plateau model. The critical value of FTSW was the threshold of FTSW where the parameters studied decreased. The thresholds increased C_S for stomatal conductance, C_T for transpiration and C_Lfor leaf water potential. Achachino showed significantly lower C_T and C_L when compared with Titicaca, implying that transpiration and leaf water potential were less affected under mild drought conditions in the Bolivian variety. C_S in Achachino was significantly higher than C_L and C_T, which indicated that stomatal conductance declined before transpiration and leaf water potential were reduced. Such difference was found in Titicaca where reduction of leaf area had more effect on transpiration than stomatal closure. Slower growth rate and smaller leaf area in combination with a lower stomatal conductance was found to contribute to drought resistance in Achachino. ABA concentration in the xylem sap tended to increase in both varieties after 2 days onset of drought, prior to decline in leaf water potential. Titicaca showed significantly (P < 0.05) higher ABA concentration when compared with Achachino under both fully irrigated and drought conditions. Titicaca had higher xylem nutrient concentration in comparison with Achachino in both fully‐watered and drought plants at day 2 after onset of soil drying. It was concluded that Titicaca was more sensitive to progressive drought than Achachino which avoided water loss by means of lower growth rate and smaller leaf area.     

冬小麦蒸腾效率对土壤水分响应的生理机制探讨

通过盆栽试验,研究了两种生态型冬小麦(石家庄8号和洛旱2号)在三种土壤水分条件下(L:田间持水量的60%~65%;M:田间持水量的70%~75%;H:田间持水量的80%~85%)蒸腾效率的变化及其生理机制。结果表明:随着土壤水分的降低,植株叶片水势降低,根冠比增加,两个品种间没有显著差异。土壤水分的降低,使植株生物量减少,蒸腾耗水减少,但蒸腾效率提高。L处理下石家庄8号和洛旱2号植株水平的蒸腾效率分别提高119.0%和62.2%。植株叶片光合速率与蒸腾速率随土壤水分的减少不断下降,但叶片水平的蒸腾效率提高,且与植株水平蒸腾效率呈极显著正相关(R2=0.96)。气孔导度随土壤水分的减少而降低,并与蒸腾速率呈极显著正相关(R2=0.97),表明蒸腾主要受气孔因素调节;光合速率随土壤水分减少而降低,但胞间CO2浓度升高,表明光合主要受非气孔因素调节,这种调节机制使得植株在干旱胁迫下更高效利用水分。试验结果初步揭示:光合与蒸腾调节机制的差异构成了试验品种在干旱下蒸腾效率提高的生理基础。     

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。     

Influence of Solar Radiation and Vapour Pressure Deficit on Transpiration Efficiency of Rainfed Sorghum

Besides assimilation, plant water relations are important aspects of physiological basis of productivity of crops in water limited environment. The relationships of photosynthesis rate, transpiration rate, leaf water potential and stomatal conductance with photosynthetically active radiation (PAR) and vapour pressure deficit (VPD) during pre-flowering (panicle initiation to ear emergence) and grain filling (from anthesis to maturity) stages of a sorghum hybrid (cv. CSH-6 ) grown under rainfed conditions were studied. Photosynthesis rate declined when PAR was above 1300 μmol m⁻² s⁻¹. during both the growth stages. Higher transpiration rate during grain filling stage at higher PAR caused the transpiration efficiency to be lower than during pre-flowering stage when PAR was above 1200 μmol m⁻²s⁻¹.Leaf water potential and stomatal conductance decreased with increase in PAR. Leaf water potential was higher during pre-flowering than during grain filling stage but maximum photosynthesis rate was similar during both the growth stages. Changes in VPD did not qualitatively alter the relationships of the physiological variables with PAR.
Decreasing photosynthesis rate and LWP at high PAR suggest that photosynthesis rate was limited by low leaf water potential when PAR was optimal, and by low PAR even when leaf water potential was high in rainfed sorghum during rainy season.     

Effect of terminal water stress on leaf epicuticular wax load,residual transpiration and grain yield in barley

The effect of drought on barley leaf epicuticular wax load (EWL), residual transpiration rates (RTR) and grain yield was examined by subjecting 12 barley genotypes to controlled irrigation and terminal water stress conditions. The mean leaf epicuticular wax load was found to be 9% greater in the plants subjected to terminal water stress than in those provided irrigation, while the mean residual transpiration rate of the irrigated plants was 20% higher than in those subjected to water stress. Under these stress conditions, the correlation between grain yield and the epicuticular wax load was positive (P < 0.01), while that between the grain yield and the residual transpiration rate was negative (P < 0.05). Under the water stress conditions, the breeding lines studied showed a greater mean epicuticular wax load than the commercial varieties, while the residual transpiration rate was greater in these varieties than in the breeding lines. The greater epicuticular wax load of the breeding lines favoured their tolerance of drought, improving their yields over those of the commercial varieties.     

乐东拟单性木兰光合、蒸腾及水分利用效率研究

运用Li-6400光合测定仪对乐东拟单性木兰的光合蒸腾特性进行了初步研究。结果表明：（1）乐东拟单性木兰的光补偿点为65.5μmol&#8226;m-2&#8226;s-1,光饱和点为1467μmol&#8226;m-2&#8226;s-1,表观量子效率为0.024;（2）乐东拟单性木兰在晴天条件下光合日变化为双峰曲线,分别在10和16时达到峰值,而在14时到达谷底,表现出午休现象。相关分析表明其影响因子主要是蒸腾速率、气孔导度和光合有效辐射;（3）乐东拟单性木兰蒸腾速率日变化近似单峰型,其主要影响因子为大气温度、叶面温度和光合有效辐射;（4）乐东拟单性木兰水分利用效率日变化为倒单峰型曲线变化。     

Physiological aspects of domestication in diploid wheat

Summary A comparative study of photosynthetic response to water stress was conducted with one genotype of wild einkorn (Triticum boeoticum, W) and one of domesticated einkorn (T. monococcum, C).Per unit leaf area, W showed a better performance for photosynthetic and transpiration activities, even under dry air and dry soil conditions. Its leaf water potential was always higher than that of C at any level of soil water potential. The difference in photosynthetic recovery from severe drought between W and C was also obvious. The photosynthetic rate, transpiration rate and water status of the leaves observed at 20 h after rewatering was almost the same as non-stressed leaves in W, whereas in C the photosynthetic rate was about half that of the non-stressed leaves, which was accompanied with a low transpiration rate and a high gas diffusion resistance. The ability of W to maintain a proper water balance over a wide range of soil water potential and to recover rapidly from severe drought seems to be a result of adaptation to its hard habitats.However, under favourable water supply, the photosynthetic rate per unit leaf nitrogen was higher in C than in W. This may be advantageous to bring about a better plant growth than W on the arable land where the improved water supply is guaranteed.     

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.