冬小麦叶片水势、气孔阻力、蒸腾速率与环境因素的关系

本文依据田间试验资料,分析了冬小麦叶片水势、气孔阻力和蒸腾速率在不同土壤基质势条件下的日变化规律,探讨了其与土壤基质势和天气条件(光照强度、净辐射、饱和差、气温)之间的关系,建立了叶片水势、气孔阻力、蒸腾速率与环境因素间的定量关系式。     

牧草抗旱机理与节水灌溉技术研究

在干旱、半干旱地区，牧草因长期处于亏水环境中，形成了一定的抗性，存在一个较宽的对水分利用相对较高的生理耗水阈值。木文从这一水分生理角度出发，在充分研究牧草生理生态适旱系列变化过程的基础上，确定了几种干旱半干旱草地的经济耗水量，并制定出相应的经济灌溉制度。     

轻小型移动式喷灌机组现状及其与国外的差距

节水灌溉是农业现代化的重要组成部分，发展节水灌溉、提高水的利用率是实现农业现代化的必由之路。通过对国内相关厂家的调研，初步分析了我国轻小型移动式喷灌机组的现状及其与国外先进水平之间存在的差距。在此基础上，提出了今后研究工作的具体目标。     

兴安落叶松容器苗化学剪根效果与根生长潜力测定的研究

采用内壁涂有不同浓度碳酸铜的容器培育出兴安落叶松(Larix gmelini(Rupr.)Rupr.)苗木,苗木侧根受碳酸铜的抑制,减小了根系变形的程度。通过对处理苗木根生长潜力的测定表明:碳酸铜浓度为100～150g/L时改变了兴安落叶松容器苗新根的分布状态,根系中、上层的新根数量明显增加,这样的苗木根系更接近自然发育的苗木根系,从而克服了一般容器苗根系易变形的缺点。     

陇东旱塬农作物生态潜力研究

在分析了陇东旱塬什字塬区农业资源的基础上,运用“农业生态区域法”(AEZ)估算了该区主要农作物的资源生产潜力,分析了限制农田生产力的主要因素,提出了进一步挖掘潜力的战略途径.     

机构持股与会计稳健性

以我国A股具有机构持股的上市公司2007~2011年的数据为样本，采用Basu(1997)的盈余-回报率模型研究了机构持股对会计稳健性的影响。结果表明：机构持股比例越高，会计稳健性越好。考虑到产权性质后，国有公司的机构持股比例与会计稳健性具有显著的正相关关系，而在非国有公司中并不显著。另外，高成长性公司中机构持股对会计稳健性的影响显著为正，但在低成长性公司这一结果不显著。     

节水型绿地中雨水的收集与利用

阐述了节水型绿地中雨水利用的可行性和必要性,探讨了雨水的收集、净化、存储与利用途径,以期为节水型绿地建设方面的研究提供帮助。     

Multi‐channel visual evoked potential as an ancillary tool to diagnose intraorbital optic nerve lesions

Multi‐channel visual evoked potential (MVEP) recording method was used to assist in diagnosing a 4‐month‐old Chinese Albino rabbit with an intraorbital mass. Subcutaneous MVEP of its both eyes were recorded simultaneously using 16 electrodes (4 × 4) multi‐channel array. Analysis of the cortical potential landscapes (CPL) showed that the conduction function of right eye was remarkably impaired in terms of decreased amplitudes and prolonged latencies. Specific side‐dominant distribution asymmetry of the decreased MVEP amplitudes indicated that the temporal side of the optic nerve (ON) was severely involved. Overall prolonged latencies of the CPL without side differences suggested that the functional impairment could have been caused by the mechanical compression exerted by an intraorbital mass. Surgical removal procedures confirmed that the mass was located temporally to the ON. Pathological examination provided a final diagnosis of a giant polycystic mucocele. Beyond its significance as a standard tool to assess functional changes of the visual pathway, MVEP recordings might assist locating intraorbital lesions that involve the ON by careful analysis of abnormal CPLs.     

Effects of Increasing Salinity Stress and Decreasing Water Availability on Ecophysiological Traits of Quinoa (Chenopodium quinoa Willd.) Grown in a Mediterranean‐Type Agroecosystem

Quinoa is a native Andean crop for domestic consumption and market sale, widely investigated due to its nutritional composition and gluten‐free seeds. Leaf water potential (Ψ_leaf) and its components and stomatal conductance (g_s) of quinoa, cultivar Titicaca, were investigated in Southern Italy, in field trials (2009 and 2010). This alternative crop was subjected to irrigation treatments, with the restitution of 100 %, 50 % and 25 % of the water necessary to replenish field capacity, with well water (100 W, 50 W, 25 W) and saline water (100 WS, 50 WS, 25 WS) with an electrical conductivity (EC_w) of 22 dS m^?1. As water and salt stress developed and Ψ_leaf decreased, the leaf osmotic potential (Ψ_π) declined (below ?2.05 MPa) to maintain turgor. Stomatal conductance decreased with the reduction in Ψ_leaf (with a steep drop at Ψ_leaf between ?0.8 and 1.2 MPa) and Ψ_π (with a steep drop at Ψ_π between ?1.2 and ?1.4 MPa). Salt and drought stress, in both years, did not affect markedly the relationship between water potential components, RWC and g_s. Leaf water potentials and g_s were inversely related to water limitation and soil salinity experimentally imposed, showing exponential (Ψ_leaf and turgor pressure, Ψ_p, vs. g_s) or linear (Ψ_leaf and Ψ_p vs. SWC) functions. At the end of the experiment, salt‐irrigated plants showed a severe drop in Ψ_leaf (below ?2 MPa), resulting in stomatal closure through interactive effects of soil water availability and salt excess to control the loss of turgor in leaves. The effects of salinity and drought resulted in strict dependencies between RWC and water potential components, showing that regulating cellular water deficit and volume is a powerful mechanism for conserving cellular hydration under stress, resulting in osmotic adjustment at turgor loss. The extent of osmotic adjustment associated with drought was not reflected in Ψ_π at full turgor. As soil was drying, the association between Ψ_leaf and SWC reflected the ability of quinoa to explore soil volume to continue extracting available water from the soil. However, leaf ABA content did not vary under concomitant salinity and drought stress conditions in 2009, while differing between 100 W and 100 WS in 2010. Quinoa showed good resistance to water and salt stress through stomatal responses and osmotic adjustments that played a role in the maintenance of a leaf turgor favourable to plant growth and preserved crop yield in cropping systems similar to those of Southern Italy.     

水分胁迫对常见绿化植物苗木光响应特性的影响

采用盆栽试验研究正常供水(黎明前小枝水势ψ-0.8MPa)和中度水分胁迫(-2.5MPaψ-3.5MPa)条件下,3种生活型绿化植物苗木光响应特性。结果表明:3种生活型苗木光响应曲线均与非直角双曲线接近;在正常供水条件下,乔木、灌木和攀援植物苗木的最大光合速率(Pnmax)分别为10.44、11.17、16.40μmol·m-2·s-1,表观光合量子效率(AQ,Y)分别为0.066、0.045、0.037,暗呼吸速率(Rd)分别为0.56、1.47、1.51μmol·m-2·s-1,光补偿点(LC,P)分别为17、33、46μmol·m-2·s-1,光饱和点(LS,P)分别为336、358、612μmol·m-2·s-1;土壤水分胁迫能显著降低乔木、灌木和攀援植物苗木的Pnmax、AQ,Y,而对Rd无显著影响,LS,P和LC,P的变化因种类而不同。在土壤水分胁迫条件下,灌木表现出较高的光合活性,其Pnmax、AQ,Y和Rd值均比乔木和攀援植物高,表明灌木苗木对土壤水分的生态适应能力较强。