Resting and Dobutamine Stress Echocardiographic Factors Associated with the Development of Occult Dilated Cardiomyopathy in Healthy Doberman Pinscher Dogs

In 29 healthy Doberman Pinschers, echocardiographic parameters evaluating systolic and diastolic function were examined prospectively at rest and during dobutamine constant rate infusion (5 μg/kg/minute) to determine if any parameters were associated with the development of occult dilated cardiomyopathy (DCM). A resting echocardiogram was repeated 1 year later to determine which dogs had met our criteria for occult DCM. Six dogs developed occult DCM during the follow-up period. Univariate logistic regression analysis showed that at rest, an increased left ventricular internal dimension in systole (LVID-S) ( P = .02), preejection period (PEP) ( P = .03), ratio of PEP to left ventricular ejection time ( P = .02), and isovolumic relaxation time ( P = .02) were significantly associated with the development of occult DCM. During dobutamine stress echocardiography (DSE), high LVID-S ( P = .02) and systolic wall stress index ( P = .04) and reduced fractional shortening ( P = .02) and ratio of peak early to late diastolic mitral filling velocity (E/A) ( P = .05) were associated with the development of occult DCM. Multiple logistic regression showed that LVID-S ( P = .002) and E/A ( P = .002) measured during dobutamine infusion also were associated with the development of occult DCM. Reclassification based on the DSE data was not significantly different than reclassification based on the resting echocardiographic data. Resting echocardiography and DSE have the potential to be clinically applicable screening tests for very early systolic and diastolic dysfunction in Doberman Pinschers, heralding the onset of occult DCM as it is currently defined.     

果树生态生理数学模拟的研究进展和应用

详细论述了数学模型在果树上的研究进展,从5个方面对果树模型的种类、模拟内容及其在科研和生产中的应用进行了阐述,即果树开花模型、果树生理模型、果树生长发育模型、果树形态模拟模型及其果树专家系统和支持决策系统。并对果树模型的发展趋势和研究重点进行了探讨,认为计算机信息技术和三维数字化技术与果树生理学和形态发育相结合的系统模型将是今后研究的重点。     

不同倍性蜜枚西瓜幼苗在低温胁迫下的生理生化特性

以蜜枚二倍体及其人工诱导的同源四倍体、三倍体为材料研究了西瓜品种的不同倍性幼苗在冷胁迫下冷害指数、细胞保护酶(SOD、POD)及PRO、MDA的变化。结果表明:在没有冷诱导时M4x、M3x的耐冷性不如M2x。随着冷胁迫时间的延长,SOD、POD活性都有所增加,M2x比M4x、M3x增加幅度大,最后下降。MDA含量变化呈相反的趋势。M2x的体内活性氧积累少,表现出比多倍体耐冷性强。PRO含量变化M2x、M3x先上升,4d后表现下降,M4x的PRO含量从开始就表现下降。     

粳稻品种Dongjin在干旱胁迫下苗期生理反应

为了明确苗期水稻对干旱胁迫的生理反应,笔者从光合作用、水分生理、植株体内的氧化逆境、渗透调节物质代谢以及细胞膜的完整性等几个方面分析了粳稻品种Dongjin（Oryza sativa L. subsp. japonica）在干旱胁迫处理下的生理变化。结果表明：干旱胁迫过程中,叶片的净光合速率与植株地上部相对含水量在处理5d内均已显著降低,5d后大幅度下降;植株地上部丙二醛含量的显著增加以及相对电导率的快速上升发生在处理5d以后,并且二者的变化趋势相类似;脯氨酸含量在处理6d时有所增加,处理6d后快速上升;叶片的活性氧含量在处理6d时略微下降,6d后逐渐上升,处理8d时显著升高。光合速率与相对含水量最先响应旱胁迫信号,与活性氧、丙二醛、脯氨酸含量和相对电导率一起可用作综合评价水稻苗期耐旱性的指标。     

两个小麦品种的抗旱性鉴定与评价

为探索小麦品种‘西农100’和‘周麦18’的抗旱特性,采用大田和盆栽组合试验,通过测定根部性状、萌发率、生理指标和显微结构等,分析其抗旱性。结果表明：‘西农100’的根质量、平均根数、根表面积与体积显著低于‘周麦18’,在水培25 d时,‘西农100’的总根长与最大根长显著高于‘周麦18’。两个品种在PEG胁迫下的发芽率都达到了90%以上,苗期抗旱性等级均为极强。两个品种在苗期干旱胁迫下的幼苗存活率较高,相对含水量无显著差异。‘西农100’在水分临界期受到干旱胁迫后,其产量显著低于‘周麦18’;两个品种的旗叶抗氧化酶(SOD、POD、CAT)活性、渗透调节物质(Pro、可溶性蛋白)含量与小麦的抗旱性呈正相关,复水后抗氧化酶活性随时间逐渐降低至对照水平,渗透调节物质含量显著降低;‘西农100’和‘周麦18’在干旱胁迫下的叶片均出现明显结构变化;总体来说,在水分临界期‘西农100’抗旱性整体弱于‘周麦18’。     

Whole-tree water balance and indicators for short-term drought stress in non-bearing ‘Barnea’ olives

Drainage-weighing lysimeters allowed monitoring of water balance components of non-bearing olive (Olea europaea cv Barnea) trees over a 3-month period including short-term events of controlled but severe water stress. The objective of the study was to evaluate a variety of soil and plant-based water status and drought stress monitoring methods on the basis of tree-scale evapotranspiration (ET). As the trees entered into and recovered from water stress, meteorological data, actual ET (ET_a), soil water content and changes in leaf turgor pressure were continuously monitored. Additionally, midday measurements of stem water potential, stomatal conductance, canopy temperature, and quantum yield of PSII photochemistry were conducted. Diurnal (dawn to dusk) measurements of all the above were made hourly on days of maximum stress. Shoot elongation rate was measured for periods of stress and recovery. Quantum yield of PSII photochemistry, stomatal conductance, and stem water potential all successfully indicated reductions in whole-tree water consumption beginning at moderate stress levels. These measured parameters fully recovered to the levels of non-stressed trees soon after water application was renewed. Shoot elongation was reduced 25-30% for the 10-day period during and following drought and recovered thereafter to levels of non-stressed trees. Whole-tree ET_a was reduced by as much as 20% even following full recovery of the leaf level parameters, suggesting reduced canopy size and growth due to the stress period. Non-destructive, continuous (turgor pressure) and remotely sensed (canopy temperature) methods showed promising potential for monitoring effects of water stress, in spite of technological and data interpretation challenges requiring further attention.     

农用地集约利用及其评价

科学评价农用地集约利用水平对于区域可持续发展有着重要意义。为此,采用资料综合分析和理论分析方法,对农用地集约利用的若干问题进行研究;在分析农用地集约利用内涵和影响因素的基础上,重点阐述了农用地集约利用指标体系的构建和评价方法,以期对我国农用地集约利用研究的发展与深化有所裨益。     

水分胁迫下常夏石竹的生理指标分析

以采种于黑龙江省亚布力林业局生态园和吉林省北华大学实验区的常夏石竹为对象,采用盆栽控水进行水分胁迫的措施设计,比较水分胁迫下两个地区常夏石竹的组织相对含水量(RWC)、质膜相对透性、脯氨酸(Pro)含量、净光合速率(Pn)等生理变化。结果表明:在水分胁迫下,亚布力的常夏石竹RWC、Pro含量相对较高,质膜相对透性相对较低;来自于吉林的常夏石竹相对较弱,即来自于亚布力的常夏石竹抵御水分胁迫的能力相对较强。     

甜樱桃嫁接苗与组培苗枝条抗寒生理差异分析

为探明自然休眠期间甜樱桃枝条内抗寒相关的生理生化指标变化规律,筛选樱桃抗寒性的主要鉴定指标,并比较嫁接苗和组培苗休眠期间抗寒性的差异,以甜樱桃嫁接苗（早红宝石/大窝娄叶）和组培苗（早红宝石）为研究对象,对自然休眠过程中的一年生枝条中可溶性糖、淀粉、可溶性蛋白、游离脯氨酸、花青素、丙二醛（MDA）等含量,过氧化物歧化酶（SOD）活性等进行分析测定。结果表明,自然休眠过程中,枝条韧皮部中可溶性糖、淀粉、可溶性蛋白及MDA含量呈现先增加后降低,且体内保护酶SOD活性先增强再减弱,枝条韧皮部厚度与枝条电导率呈负相关,这些均可以作为樱桃抗寒性鉴定的指标,休眠期嫁接苗和组培苗抗寒生理指标多数取样点差异不显著。自然休眠过程中嫁接苗和组培苗枝条抗寒生理指标在休眠过程中出现相似的规律,嫁接苗与组培苗的抗寒性差异不显著。因此,考虑组培苗可以在嫁接苗栽培区试用推广。     

碱化橄榄油加工废弃液对玉米种子萌发及幼苗生长的影响

通过研究橄榄油加工废弃液对玉米种子萌发及幼苗生长的影响,为橄榄油废弃物利用以及农田环境保护提供参考。将橄榄油加工废弃液（10%~60%）用0.10% Na₂CO₃碱化处理,考察其对玉米种子萌发、幼苗生长以及生理生化特性的影响。30%碱化废弃液能显著促进玉米种子萌发和幼苗生长,随废弃液浓度升高,种子萌发率显著降低,幼苗生长和生物量受阻,幼苗整齐度降低,叶片O₂ ^-·产生速率先升高后降低,H₂O₂、游离脯氨酸、可溶性糖和丙二醛含量显著增加,超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶