水分胁迫效应对冬小麦生长发育影响的试验研究

利用大型水分试验场遮雨棚遮挡自然降水 ,采用人工定量补水进行冬小麦土壤含水量占田间持水量 4 0 %～ 5 0 %、4 5 %～ 5 0 %、5 0 %～ 5 5 %、5 0 %～ 60 %、5 5 %～ 60 %、60 %～ 70 %持续时间分别为 5、1 0、1 5 d水分胁迫处理的控制试验。试验结果表明 :控制期结束复水后 ,5 0 %～ 60 %、5 5 %～ 70 %水分胁迫处理能诱发冬小麦根、茎、叶、总生物量显著增长或明显减缓其衰老速率。土壤含水量占田间持水量 5 0 %～ 60 %处理 ,具有明显的增产、节水效应。确定土壤含水量占田间持水量 5 5

夏玉米水分胁迫效应的试验研究

利用光合测定系统对夏玉米灌浆前期叶片水汽交换的参数进行了系统测定,得出叶片净光合速率、蒸腾速率、叶片温度、气孔导度与水分利用效率的关系。结果表明,3种水分处理的净光合速率、蒸腾速率和水分利用效率都有大体一致的日变化过程,但又体现了不同水分处理的差异性。胁迫处理的水分利用效率大于湿润处理和干旱处理。水分利用效率与净光合速率、蒸腾速率的关系有很大的相似性,当净光合速率<20μmol/m^2·s时,水分利用效率基本无变化,当20μmol/m^2·s<净光合速率<26μmol/m^2·s时,水分利用效率增长最快;当蒸腾速率<5mmol/m^2·s时,水分利用效率变化不大,在5mmol/m^2·s<蒸腾速率<7mmol/m^2·s时,水分利用效率增长最快;当净光合速率>26μmol/m^2·s和蒸腾速率>75mmol/m^2·s时,水分利用效率均呈现下降趋势。水分利用效率对叶片温度有很强的敏感性,在40℃<叶片温度<42℃时,水分利用效率迅速增加。随气孔导度的增大,水分利用效率呈上升趋势,在140mmol/m^2·s<气孔导度<200mmol/m^2·s时,水分利用效率上升最快,气孔导度再增大时,水分利用效率趋于稳定甚或下降。

冬小麦中轻度水分胁迫的增产节水效应研究

利用大型水分试验场的防雨棚遮挡自然降水,采用人工定量补水进行冬小麦土壤含水量占田间持水量40%～50%、45%～50%、50%～55%、50%～60%、55%～60%、60%～70%持续时间分别为5、10、15天水分胁迫处理的控制试验。试验结果表明:50%～70%的中轻度水分胁迫处理,冬小麦具有显著的增产节水效果;2年平均,增产6.3%～7.4%,节水28.2%～34.1%。中轻度水分胁迫下,冬小麦增产节水作用机制的实现,主要是通过水分胁迫效应诱发增强:①冬小麦根系的找水功能;②产量构成因子的优化;③复水后光合速率的提高。冬小麦水分胁迫效应的最佳利用时间为返青-拔节期,此时进行水分胁迫效应利用最有利于冬小麦稳产增产。

玉米穗期水分胁迫对产量和水分利用效率的影响

在盆栽条件下,以 6个玉米杂交种为试验材料,研究了玉米穗期正常供水、轻度和中度水分胁迫下产量和水分利用效率 (WaterUseEfficien cy,简称WUE)的变化。结果表明, 6个玉米品种的产量和耗水量的水分胁迫效应均显著,随胁迫程度加大,产量和耗水量均明显降低,但不同品种对水分胁迫的反应存在差异。轻度水分胁迫下,供试品种中有两个品种表现出产量下降幅度不大、且比耗水量下降幅度小、WUE有所提高的优良特性;中度水分胁迫下, 6个品种均表现为产量大幅度下降,且远高于耗水量的下降幅度,导致WUE明显降低。相关分析表明, 3种供水条件下,WUE与产量均呈显著正相关,与耗水量的相关性均不显著。

绿豆地膜覆盖栽培密度研究

我区中西部食用豆以绿豆为主。干旱、贫瘠、早春低温等是该地区的生态特点。干旱是影响食用豆产量的重要障碍因子，因干旱产生的水分胁迫效应对绿豆产量的降低作用大于其他自然灾害的总和。“十一五”期间，我们对地膜覆盖绿豆栽培做了系统的研究，基本明确地膜覆盖具有抗旱、保墒、提高地温、减少田间杂草和较好的增产作用，并进行较大面积的示范推广，但绿豆地膜覆盖栽培均采用玉米播种机播种覆膜，存在密度偏小，群体结构不合理的问题。2011—2012年连续两年，我们对不同类型绿豆品种地膜覆盖合理的群体密度进行了研究，

Effects of Water Stress on Some Physiological Characteristics and Yield Compensation of Rice in Booting Stage

[Objective] The physiological characteristics and yield compensation effects of rice in booting stage were studied after water recovery when rice suffered water stress to provide references for improving rice water utilization efficiency and its drought resistance. [Method] The pot experiments with five rice varieties under three different treatments of water stresses were conducted to study physical signs every six days after water water-recovery. [Result] Along with the increase of water recov- ery, leaf water potential, SPAD and Pn values in treatment B （light drought） in- creased fast, and its compensation effect of the soluble sugar content was higher than that of treatment C （severe drought）; all sap flow speeds in treatments with water stresses fell. As for yield components, panicles per plant and spikelets per panicle decreased with water stress degree, and the decline of spikelets per pani- cle, in particular, was greatly influenced by water stress. Seed setting percentages in treatment B most reached peaks of different varieties, except of D you No. 363. The thousand-seed weight and ear weight per plant in treatment B and C both dropped, compared with control group. [Conclusion] When regular management was resumed after rice underwent water stress at booting stage, many characteristics and yield traits of rice got favorable compensation effects in the light water-stress treatments.

Effects of Gradual Water Deficit Stress on Phenological and Morphological Traits in Chickpea （Cicer arietinum L.）

The aims of this study were to investigate the effect of gradual water deficit stress on some phonological and morphological traits and grain yield of desi and kabuli chickpea cultivars. This study was carried out in 2007 and 2008, to evaluate responses of three chickpea cultivars （Hashem and Arman from kabuli and Pirooz from desi type） under well watering （I1： 70mm evaporation from class A pan）, gradual water deficit （12 and 13： 70→90→ 110→130 and 70→100→130mm evaporation from class A pan, respectively） and severe water stress （14： 130mm evaporation from class A pan）. Result showed that days to flowering and plant height were decreased, as water limitation increased. This reduction was significant under gradual water stress （I2 and I3） and Severe water deficit （I4）, compared with control （I1）. There were no significant differences in grain filling period and grain yield among I~, I2 and I3 irrigation treatments. No significant differences in days to physiologic maturity and number of sub branches were recorded among irrigation treatments. Interactions of year×cultivar for days to physiologic maturity, grain filling period and grain yield （P≤0.01） and for days to flowering and plant height （P≤0.05） were significant. The superiority of Arman in producing comparatively greater grain yield could be attributed to higher grain filling period of this cultivar in both years.