抗旱、耐盐碱、矮秆陆地棉数量性状的遗传相关及主成份分析

对从国内外引进的抗旱、耐盐碱、矮杆棉花资源材料 ,经抗旱、耐盐碱、矮杆性鉴定和比较 ,选取了其中表现较好的 1 9份材料 ,进行了遗传相关和主成份分析 ,结果表明 :在 5 0 mmol· L- 1Na Cland1 0 0 mmol· L- 1Na Cl胁迫下的出苗率间呈正相关 ,抗盐性与产量间呈负相关 ;第一棉铃高度与纤维品质性状呈正相关。抗旱、耐盐碱、矮杆棉花材料的前 6个因子贡献率达 86.5 % ,其分别为第一棉铃高度因子、果枝数因子、单株结铃数因子、矮杆因子、单铃重因子等     

Urinary catecholamine and metanephrine to creatinine ratios in healthy dogs at home and in a hospital environment and in 2 dogs with pheochromocytoma

BACKGROUND: Measurement of high concentrations of urine catecholamines and metanephrines is useful in diagnosing pheochromocytoma in humans. Stress increases catecholamine excretion in urine. HYPOTHESIS: Stress of a hospital visit increases urinary catecholamine and metanephrine excretion in dogs. ANIMALS: Fourteen clinically normal dogs, 2 dogs with pheochromocytoma. METHODS: Voided urine samples were collected by the owners 7 days before (t-7), during the hospital visit immediately after diagnostic procedures (t0), as well as 1 (t1) and 7 days (t7) after the hospital visit. Urine catecholamine and metanephrine concentrations were measured using high-pressure liquid chromatography and expressed as ratios to urine creatinine concentration. RESULTS: In client-owned dogs epinephrine and norepinephrine ratios at t0 were significantly higher compared with ratios at t7. Metanephrine and normetanephrine ratios at t-7, t0, and t1 did not differ significantly from each other; however, at t7 they were significantly lower compared to values at t-7. In staff-owned dogs no significant differences were detected among the different collecting time points for any variable. Metanephrine and normetanephrine ratios were significantly higher in client-owned dogs compared to staff-owned dogs at t-7, t0, and t1 but not at t7. CONCLUSIONS AND CLINICAL IMPORTANCE: Stress associated with a hospital visit and with the sampling procedure causes increases in urine catecholamine and metanephrine excretion. Urine collection for the diagnosis of pheochromocytoma probably should take place at home after adaptation to the sampling procedure.     

Quantification of stress sensitive markers in single fecal samples do not accurately predict excretion of these in the pig

All feces produced during 24 h were collected from five pigs and cortisol and immunoreactive cortisol metabolites (CICM), and IgA were quantified. Within pigs, the concentrations of CICM and IgA varied extensively between random samples obtained from a single fecal dropping, and deviated in most cases significantly from the true concentration measured in total fecal output (CV 6.7-130%). The CICM and IgA contents varied considerably (CV 8.1-114%) within and between individual fecal droppings from the same pig compared to the total fecal excretion. In conclusion, single random samples could not be used to reliably quantify the total fecal concentration or excretion of CICM or IgA in pigs. Analyses of all feces collected during shorter periods than 24 h did not provide an accurate estimate of the daily excretion of CICM. Thus, the concentration of stress sensitive molecules in random single fecal samples as an indicator of animal welfare should be interpreted with prudence.     

不同基因型大麦苗期对干旱胁迫的响应及HvPIPs基因表达特征分析

为研究不同基因型大麦苗期对干旱胁迫的响应,挖掘优质抗旱的大麦种质资源,以4份不同基因型大麦(2个高抗品种ZDM5430和ZDM5458,2个干旱敏感型品种7DCADA和IL-12)为材料,利用聚乙二醇(PEG-6000)模拟干旱条件,综合分析不同品种大麦的苗期抗旱性差异;并通过对不同品种根系进行PIPs实时定量分析,研究水通道蛋白AQPs基因与干旱胁迫之间的应答关系。结果表明,持续干旱胁迫会使大麦生长变缓,各处理苗长、根长、叶含水量和根含水量都呈下降趋势,其中,4个品种的大麦叶含水量在干旱胁迫14 d时下降最为显著,与对照相比,其降幅分别为29.14%、52.64%、21.67%和72.15%。干旱胁迫对大麦苗期干物质积累量和根冠比的影响较小,各处理间差异不显著;但持续干旱后,抗旱品种ZDM5430的根冠比呈上升趋势,在胁迫7、14、21 d时较CK分别增加了4.92%、42.86%和21.05%。随着胁迫时间的延长,大麦旗叶叶绿素含量和根系活力也呈下降趋势,其中ZDM5430和ZDM5458较对照组降幅较小,说明抗旱品种的形态指标、叶绿素含量及根系活力受干旱胁迫的影响较小。通过PIP...     

基于AHP-EWM-TOPSIS的温室辣椒最佳调亏灌溉方案优化研究

辣椒对土壤水分非常敏感,传统的灌溉方式以单一追求高产为目的,对农作物进行大量灌溉,辣椒产量的提高往往伴随品质的下降。为选出能平衡产量和品质的最优调亏灌溉方案,本试验以辣椒为研究对象,以全生育期充分供水(75%～85%θ_f,θ_f为田间持水量)作为对照(CK),在3个调亏时期(苗期M、花期H和果期G)分别设置2种调亏程度(轻度水分调亏LS:65%～75%θ_f,重度水分调亏SS:55%～65%θ_f)和2种调亏历时(短期调亏：连续亏水4 d,长期调亏：连续亏水8 d),研究不同调亏处理对辣椒生长、产量和品质的影响。结果表明,在各生育期进行调亏灌溉均会减小辣椒株高、茎粗、叶面积及营养器官干物质。与花期和果期相比,苗期水分调亏对辣椒生长指标及营养器官干物质的抑制程度最大,尤其在苗期长期重度水分调亏(MSS-8)下,营养器官干物质最少,较CK下降27.85%。另外,苗期和花期适度的水分调亏有利于提高辣椒生殖器官干物质和产量,其中,苗期短期轻度(MLS-4)、苗期长期轻度(MLS-8)及花期短期轻度(HLS-4)水...     

减振器多片叠加节流阀片特性分析与试验研究

通过减振器节流阀片的力学模型,建立了节流阀片弯曲变形的微分方程,得到了阀片弯曲变形系数和在任意位置的弯曲变形计算公式。对多片节流阀片叠加进行了深入的研究,得到了叠加阀片当量厚度计算公式。对叠加阀片上所受最大应力进行了探讨,对叠加阀片与当量厚度阀片所受最大应力之间的关系进行了研究,得到了叠加阀片应力系数与厚度系数。通过实例,对叠加阀片的最大应力进行了分析计算和仿真,对不同当量厚度和相同当量厚度的叠加阀片对减振器阻尼特性的影响进行室内对比性试验。仿真和试验表明,叠加阀片的弯曲变形、当量厚度和最大应力的分析计算方法是正确的,对减振器的特性分析和优化设计具有理论和实际参考价值。     

A reservoir operational rule for irrigation in Japan

Operation of a reservoir for irrigation is more complicated and difficult than that for domestic water supply in Japan, owing to the fact that a requirement for irrigation takes various value depending upon effective rainfall on farmland, soil condition, and so on. Therefore, the reservoirs should be operated to correspond with demand, inflow, and unknown droughts occurring in the future. However, the reservoirs have been operated under operators' experiences without formal operational rules, because any effective theories or methods have been neither developed nor used in Japan at present.On operation of the reservoirs, there are two targets — promotion of effective release and restriction of release in preparation for droughts — conflicting with each other. It is useful to set up the operation with Required Storage for Drought Curve (RSDC) Method to achieve reasonable operation harmonizing those two targets. RSDC is composed with Target Line (TL) and Restrictive Release Lines (RRLs). TL is a target storage level to guarantee that storage will never empty until the end of the irrigation period under a certain probability. If actual storage remains above TL, effective release will be promoted. RRLs are storage levels pointing out the basis of restricting release. If actual storage falls below TL, release will be restrained in accordance with RRLs in order to get over uncertain droughts occurring in the future.In this paper, the theory of RSDC is described and the effectiveness of Rule Curve (RC) based on RSDC Method is illustrated by simulation on a single reservoir for irrigation.     

防旱减灾经济效益计算方法初探

利用大量的统计资料，研究了防旱减灾经济效益的计算方法，其中重点提出了临时抗旱措施的经济效益计算方法，可供今后计算抗旱效益时应用和参考。     

Case study on an integrated operation planning of multiple reservoirs for irrigation in Japan

In spite of several attempts at integrated operation planning, multiple reservoirs in Japan have been operated by trial and error without any formal rules. Subjects of integrated operation are not only showing optimal usage of daily storage levels as an operational policy but also providing a countermeasure for droughts.Objectives of this study are to make a formal operation rule of multiple reservoirs for irrigation using the theory of Required Storage for Drought Curve (RSDC) Method and to propose operational policy for multiple reservoirs as large water supply systems. The Iwaki river basin, on which there are four reservoirs for irrigation parallel with each other, is considered to be a model river basin with a large water system for this case study.From results of simulations using historical data, comparing an individual operation rule with an integrated operation rule on several indices, effectiveness of the latter rule is recognized. Under integrated operation, water losses are minimized and excessive water conservation can be avoided over the whole area to benefit while target river discharge is maintained at key control points because water usage from all reservoirs is well balanced in relation to water availability.     

Cover crop evapotranspiration under semi-arid conditions using FAO dual crop coefficient method with water stress compensation

Cover cropping is a common agro-environmental tool for soil and groundwater protection. In water limited environments, knowledge about additional water extraction by cover crop plants compared to a bare soil is required for a sustainable management strategy. Estimates obtained by the FAO dual crop coefficient method, compared to water balance-based data of actual evapotranspiration, were used to assess the risk of soil water depletion by four cover crop species (phacelia, hairy vetch, rye, mustard) compared to a fallow control. A water stress compensation function was developed for this model to account for additional water uptake from deeper soil layers under dry conditions. The average deviation of modelled cumulative evapotranspiration from the measured values was 1.4% under wet conditions in 2004 and 6.7% under dry conditions in 2005. Water stress compensation was suggested for rye and mustard, improving substantially the model estimates. Dry conditions during full cover crop growth resulted in water losses exceeding fallow by a maximum of +15.8% for rye, while no substantially higher water losses to the atmosphere were found in case of evenly distributed rainfall during the plant vegetation period with evaporation and transpiration concentrated in the upper soil layer. Generally the potential of cover crop induced water storage depletion was limited due to the low evaporative demand when plants achieved maximum growth. These results in a transpiration efficiency being highest for phacelia (5.1 g m⁻² mm⁻¹) and vetch (5.4 g m⁻² mm⁻¹) and substantially lower for rye (2.9 g m⁻² mm⁻¹) and mustard (2.8 g m⁻² mm⁻¹). Taking into account total evapotranspiration losses, mustard performed substantially better. The integration of stress compensation into the FAO crop coefficient approach provided reliable estimates of water losses under dry conditions. Cover crop species reducing the high evaporation potential from a bare soil surface in late summer by a fast canopy coverage during early development stages were considered most suitable in a sustainable cover crop management for water limited environments.