低温胁迫对柳杉不同无性系的影响及抗寒性评价

通过分析柳杉不同无性系抗寒性的差异,评价柳杉不同无性系抗寒能力,为柳杉的引种栽培及抗寒育种提供理论依据。以生长一致的10个柳杉无性系的2年生枝条为试验材料,分别在4℃、0℃、-4℃、-8℃、-12℃、-16℃和-20℃目标低温下处理12 h,对其叶片的丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性及叶绿素荧光参数进行测定,结合主成分分析及隶属函数计算对测定的指标进行综合评价和抗寒性排序。结果表明,低温胁迫下随着温度逐渐降低,MDA含量在一定温度范围内具有一定的波动性,但总体上呈现先上升后下降再上升的趋势;SOD活性在低温初期先出现短暂的下降后经抗寒锻炼呈现出上升又下降的趋势;柳杉不同无性系PS II最大光化学效率(Fv/Fm)和PS II的实际光合量子产量(Y(II))表现出相似的变化趋势,其值在0℃达到最高,0℃之后持续降低;光化学淬灭系数(qP)在低温初期无明显变化,0℃后随着低温胁迫的加剧而降低。柳杉不同无性系抗寒性具有显著差异,其中57#、68#和32#无性系抗寒性较强,3#、25#和42#无性系抗寒性较弱。     

低温胁迫下6种木兰科植物的生理响应及抗寒相关基因差异表达

分析了6种木兰科植物对低温胁迫的生理响应及耐寒相关调控基因HSP90和WRKY33的差异表达,为木兰科植物抗寒机理的研究和抗寒品种的选育提供理论基础。结果表明,6种木兰科植物的低温LT50在-10.64—-22.06℃,从高到低依次为红花深山含笑、峨眉含笑、杂交含笑、阔瓣含笑、六瓣含笑和乐东拟单性木兰;低温过程中,6种木兰科植物叶片可溶性蛋白(SP)、游离脯氨酸(Pro)含量、超氧化物歧化酶(SOD)和过氧化物歧化酶(POD)活性呈先升高后降低的趋势,可溶性糖(SS)和丙二醛含量(MDA)则不断积累;筛选出REC、MDA、SP、SS和Pro作为6种木兰科植物抗寒性评价的关键指标;聚类分析将6种木兰科植物在抗寒性能上分为强、中、弱三类,分别为乐东拟单性木兰和六瓣含笑,阔瓣含笑、杂交含笑和峨眉含笑,以及红花深山含笑。对HSP90、WRKY33基因的差异表达分析表明,2个基因在6种木兰科植物中的相对表达量呈先升高后降低的趋势,在临近各树种LT 50时,2个基因的表达被强烈抑制且后期表达量不可逆。0℃时,2个基因的表达量差异不显著;-5℃时,2个基因开始被激活,表达量增加;-10℃时,HSP90、WRKY33基因在红花深山含笑叶片中的表达量较-5℃时分别下调了0.76倍和0.68倍,而在其他5个树种中的表达被进一步激活;-15℃时,HSP90和WRKY33基因在抗寒性中等的阔瓣含笑、杂交含笑、峨眉含笑中亦被强烈抑制,较-10℃时分别下调了0.38倍、0.33倍、0.32倍和0.71倍、0.72倍、0.74倍,在抗寒性强的乐东拟单性木兰和六瓣含笑中的表达被进一步激活;-20℃以后,2个基因在6个树种中的表达均被强烈抑制,但在抗寒性最强的乐东拟单性木兰中的表达量仍高于其他5个树种。抗寒基因的激活与表达是影响植物抗寒性的重要因素,抗寒性不同的树种对低温的应答机制明显不同。抗寒性越强的树种越能快速启动低温应答机制,激活抗寒相关基因的表达,进而调整生理生化活动以抵御和适应冷应力。不抗寒树种中抗寒基因的表达则受到抑制,降低了其对低温逆境的耐受能力。     

自然降温过程中5个常绿阔叶树种的抗寒性分析

对自然降温过程中(2006年10月至2007年3月)乐昌含笑(Michelia chapensis Dandy)、红花木莲[Manglietia insignis(Wall.)Bl.]、浙江樟[Cinnamomum japonicum Sieb.var.chekiangense(Nakai)M.P.Tang et Yao]、秃瓣杜英(Elaeocarpus glabripetalus Merr.)和乐东拟单性木兰[Parakmeria lotungensis(Chun et C.H.Tsoong)Lawl5种常绿阔叶树种的叶片相对电导率和低温半致死温度(LT50)进行了测定,并分析r各树种的LT50与月平均最低温度的相关性.结果显示,在自然降温过程中,5个树种叶片的相对电导率有明显变化,除乐东拟单性木兰外,其他树种的相对电导率均呈现先升后降再升高的变化趋势.实验期内,乐东拟单性木兰和浙江樟的LT50为-13℃～-19℃,抗寒能力较强,其他3个树种的LT50为-3℃～-11℃,抗寒能力较弱.根据LT50,可将5个树种的抗寒适应性分为抗寒性较弱期、抗寒性增强期、抗寒性最强期和抗寒性减弱期4个时期.各树种在不同月份的LT50与月平均最低气温的变化趋势一致,其中乐东拟单性木兰的LT50与月平均最低温度极显著相关.研究结果表明,乐东拟单性木兰和浙江樟的抗寒能力较强,在南京的适应性较强,可以广泛栽植.     

电导率与极端低温分布在闽中桉树引种决策上的研究

依据闽中地区永安市1971～2005年的极端低温与极值分布数学模型和气象学原理,探讨5～10 a内该区域不同海拔高度可能出现的极端异常低温,利用电导率测定引种区所引种的不同抗寒程度的桉树种的半致死温度,事前评价引种的可行性.首次提出利用极端低温与电导率进行引种决策,并把该方法称作"极端环境反应法".结果表明:在出现10 a以上异常低温时,邓恩桉(Eucalyptus dunnii)在该区域垂直分布可达海拔775 m,巨桉(E.grandis)及相近抗寒能力的桉树可在海拔467 m以下栽植,赤桉(E. camaldulensis)可在海拔960 m以下栽植.该方法可广泛应用于其它区域与不同树种引种的事前评价与决策.     

微管的冷稳定性与植物抗寒性关系的研究

利用间接免疫荧光的细胞化学技术对番茄、黄瓜、菠菜、甜菜及小麦等不同抗寒性植物微管的冷稳性进行了比较研究。结果指出,不抗寒的喜温性植物番茄和黄瓜的气孔保卫细胞的微管在0℃—1℃冷处理3小时即解聚;属于中等抗寒性植物的菠菜和甜菜幼苗经秋季低温锻炼后,其气孔保卫细胞的微管在0℃和—5℃低温处理3小时,均不发生解聚;具有较强抗寒性的冬小麦品种农大139幼苗在2—3℃低温锻炼期间,微管结构保持完整,经过15天低温锻炼的幼苗在-8℃冰冻处理3小时,微管也不受破坏。这些结果表明,微管的冷稳性与植物的抗寒性成正相关。     

温度对中华蜜蜂和意大利蜜蜂个体主要抗寒生理指标的影响

【目的】为了探究中华蜜蜂Apis cerana cerana和意大利蜜蜂Apis mellifera ligustica个体耐寒性差异的生理机制。【方法】本试验分别对20日龄的中华蜜蜂和意大利蜜蜂工蜂进行0、10、25℃持续4 h的温度处理,随后测定不同温度处理后两蜂种体内葡萄糖、甘油和氨基酸的含量。【结果】低温状态下中华蜜蜂体内葡萄糖含量显著降低,意大利蜜蜂在0℃组显著下降却在10℃组显著上升;中华蜜蜂体内甘油在低温环境下显著积累,意大利蜜蜂体内甘油水平在10℃时显著的上调却在0℃组无显著变化;中华蜜蜂体内17种氨基酸在各温度处理间显著变化,且多数的氨基酸含量表现出10℃组降低而0℃组积累的趋势,意大利蜜蜂体内只有15种氨基酸参与机体的抗寒机制,其中多数的氨基酸表现为低温环境下大量积累,仅有亮氨酸和精氨酸表现为低温时被转化消耗的现象。【结论】低温条件下可引起两蜂种体内葡萄糖、甘油和氨基酸含量的显著变化,初步推测蜜蜂体内可能存在"葡萄糖-甘油-氨基酸"的抗寒物质系统,但两蜂种在不同程度的低温处理后各生理指标的变化存在较大的差异,从一定程度上阐释两蜂种抗寒性的差异。本研究为蜜蜂个体抗寒生理机制的进一步研究提供基础数据,同时为蜜蜂抗寒新品系的选育提供理论依据。     

不同油橄榄品种对低温胁迫的生理响应及抗寒性综合评价

为了明确油橄榄的抗寒机理,对甘肃陇南地区主栽的6个油橄榄品种离体叶片进行低温胁迫(5℃、0℃、-5℃、-10℃)处理,并以18℃常温培养为对照,测定与抗寒性相关的生理生化指标,并采用隶属函数法对不同品种抗寒性进行综合评价。结果显示:(1)各油橄榄品种离体叶片相对电导率随处理温度的降低而呈"S"型曲线变化,结合Logistic方程得出不同品种油橄榄半致死温度介于-6.687℃~-3.706℃之间,且各品种的半致死温度顺序为‘皮肖利’<‘配多灵’<‘莱星’<‘阿斯’<‘鄂植8号’<‘佛奥’,其抗寒性大小依次为‘皮肖利’>‘配多灵’>‘莱星’>‘阿斯’>‘鄂植8号’>‘佛奥’。(2)随着胁迫温度降低,各油橄榄品种离体叶片叶绿素含量逐渐降低,可溶性糖含量基本呈逐渐增加趋势,而可溶性蛋白质含量、脯氨酸含量、丙二醛含量、SOD活性、POD活性和CAT活性则呈先升后降的趋势。(3)在-10℃低温胁迫下,油橄榄品种‘皮肖利’和‘配多灵’的叶片叶绿素含量比常温对照降幅较小,渗透调节物质含量和保护酶活性相对增幅较大,丙二醛含量增幅较小,而此时品种‘佛奥’和‘鄂植8号’各指标的变化趋势与之相反。(4)根据不同油橄榄品种的平均隶属度(抗寒性综合评价值)确定的品种抗寒能力大小顺序(‘皮肖利’>‘配多灵’>‘莱星’>‘阿斯’>‘鄂植8号’>‘佛奥’)与品种半致死温度的抗寒性表现顺序完全一致。研究表明,在低温胁迫条件下,‘皮肖利’和‘配多灵’等油橄榄品种能通过提高渗透调节物质含量和增强保护酶活性来缓解胁迫造成的过氧化伤害,从而表现出较强的抗寒能力;基于相对电导率的半致死温度和隶属函数法的综合评价均能准确鉴定油橄榄的抗寒性。     

长白落叶松无性系抗寒性比较研究

以58个长白落叶松无性系1年生枝条为材料,对其进行低温胁迫处理,探讨不同无性系抗寒差异,结果表明：不同温度和时间的处理条件下,4个落叶松无性系电导率不同,随着低温胁迫时间的延长和温度的降低,不同无性系电导率呈上升趋势。在相同温度及时间处理条件下（-40℃、12 h）,58个长白落叶松无性系相对电导率差异达极显著水平（P<0.01）。以-40℃、12 h处理下各无性系电导率与对照的差值为指标,利用聚类法进行分析,初步筛选出9个抗寒性较强的无性系（L5、L16、L21、L23、L27、L40、L73、L78和L90）,这些无性系可作为抗寒优良无性系进行考察,本研究为落叶松抗寒良种选育提供基础。     

低温天气对厦门姜目植物危害调查

2016年1月22~27日厦门地区出现近二十多年来未遇的极端低温天气,厦门植物园的姜目植物受到不同程度的危害。将姜目植物受害程度划分为6个受害等级,调查园内38种姜目植物的受害情况。结果表明,38种姜目植物中有34种受不同等级冻害,未受害仅4种;姜科和旅人蕉科表现较为耐寒,蝎尾蕉科和闭鞘姜科抗寒性差;山姜属抗寒能力强,蝎尾蕉属、闭鞘姜属抗寒能力弱。研究表明,原产地纬度与姜目植物抗寒能力显著相关,原产于低纬度的姜目植物易受低温危害;原产地海拔也影响姜目植物抗寒能力。     

低温胁迫下芒果苗的受害症状及生理响应

以1年生芒果嫁接苗(台农1号)为试验材料,对人工气候箱设置2、1、0、-1、-2和-3℃共6个日最低温(Tmin),在日较差分别为15℃和6℃下处理1~3 d。观察处理后芒果苗的叶片变化情况,并取其叶片测定超氧岐化酶活性、可溶性糖、游离脯氨酸和可溶性蛋白含量,以及离子渗出率、丙二醛含量等生理生化指标。综合叶片受害症状、生理指标与Tmin及其持续时间的关系,确定芒果苗期的低温受害指标,并在5个地理移置点进行自然低温试验,验证和完善芒果苗的短期寒害指标。结果表明:极端最低气温低于-1℃时芒果苗死亡;极端最低气温高于3℃(≤3 d)芒果苗正常生长;极端最低气温在3~5℃持续9 d,芒果苗的叶片无受害症状。本文结果可为芒果种植区划及引扩种提供参考。     

Comparative study of circadian variation in oral,tympanic, forehead,axillary and elbow pit temperatures measured in a cohort of young university students living their normal routines

The primary objective of the present research work is to study and compare the circadian variability in body temperature recorded from different locations of the body during subjects’ normal routines. Temperatures of oral cavity (sublingually), tympanum, forehead, axilla and the elbow pit were measured simultaneously at approximate 1-h intervals for five consecutive days during subjects’ waking span in their routine living condition. The observations were made in eight young, apparently healthy, university students. Data were analysed using cosinor rhythmometry for evaluation of circadian rhythms and two-way ANOVA with repeated measures to assess the effect of time of day and measuring site on body temperatures and their interaction. Significant circadian rhythms in body temperature, irrespective of site, were found. Based on autocorrelation analysis, it was observed that the day-to-day variability in body temperature was consistent. The acrophases of all the studied temperature rhythms were located in the afternoon, except axillary temperature, which occurred in the early evening. The mean daytime temperature was found to be the highest when recorded sublingually and it was the lowest on the forehead or elbow pit. On the basis of the results of this study, we recommend that the methods used could be introduced into laboratory courses in a curriculum of chronobiology courses for both UG and PG classes for the demonstration/study of circadian rhythms in body temperature under normal routines. The methods used are valuable as they are non-invasive, easily accepted and assessable in a student setting.     

灰飞虱发育起点温度及有效积温的探讨

利用培养箱在恒温条件下饲养灰飞虱Laodelphax striatellus Fallén,测定了卵、若虫、成虫繁殖前和全世代发育历期,用直线回归法计算了灰飞虱各虫态和全世代的发育起点温度和有效积温分别为10.06、6.43、10.29、8.08℃和102.3、365.2、87.5、552.1日·度。并根据有效积温法则预测了该虫在济宁市1年完成的代数为4～5代。     

桑树(Morus alba)朱砂叶螨（Tetranychus cinnabarinus）实验种群的温度效应

采用生命表分析、生存分析、"王-兰-丁"模型及线性模型等分析方法,对15～28℃温区的5个恒温处理朱砂叶螨(Tetranychus cinnabarinus)实验种群进行了系统研究.结果表明,此温区内,种群在生殖、发育和生存3方面,有明显的温度效应:内禀增长力、周限增长力、净增殖力和平均日产卵量、世代平均周期、及种群倍增时间的倒数呈线性增长;而平均寿命、最大死亡年龄,随温度升高而递减;性比和实际产卵天数对温度不敏感.种群在生殖、发育和生存三者之间,采取了较为"折衷"的策略:8℃为发育临界点;13℃左右为生殖和种群增长临界温度;22℃左右为生殖和种群增长最适温度;30℃左右为发育最适温度.     

竹织叶野螟发育起点温度和有效积温

采用19,22,25,28和31℃5个温度对竹织叶野螟Algedonia coclesalis Walker各虫态(龄)发育起点温度和有效积温进行测定。结果表明,竹织叶野螟的在19～31℃范围内均能正常生长发育,尤其是28～31℃范围最适宜于竹织叶野螟的生长发育。卵、1龄幼虫、2龄幼虫、3龄幼虫、4龄幼虫、5龄幼虫、6龄幼虫、7龄幼虫、蛹、成虫及世代的发育起点温度分别为6.63,12.51,11.18,10.93,10.05,8.01,6.80,5.78,6.20,7.81和8.33℃,有效积温分别为124.19,64.54,72.59,82.08,93.46,136.84,155.42,201.06,211.55,111.49和1235.50日.度。     

核桃扁叶甲的发育起点温度和有效积温

室内观察测定5个恒温条件下,核桃扁叶甲Gastrolina depressa Baly各虫态的发育历期及起点温度和有效积温。结果表明:在16～32℃温度范围内,核桃扁叶甲均能完成发育,其发育历期随温度的升高而缩短,卵期、幼虫期、蛹期、产卵前期的发育起点温度分别为9.4,12.2,14.3和11.1℃,有效积温分别为43.2,77.2,36.0和104.7日.度;整个世代的发育起点温度为12.0℃,有效积温为260.5日.度。持续过高温度不适合核桃扁叶甲的生长发育。     

Evaluation of the cold strain index (CSI) for peripheral cold environmental stress

The purpose of this study was to evaluate the cold strain index (CSI) for peripheral environmental stress using data from a previous footwear study. Eight men (20±2 yr) dressed in protective cold weather clothing with varying footwear underwent 5 days of cold air (−23.4 °C) testing while attempting to sit for 240 min. Rectal, skin, and toe temperatures (T_toe) were continuously measured. All test exposures were ended after 50–165 min due to cold foot discomfort or T_toe<5 °C. However, CSI values indicated little cold strain. Therefore, we revised CSI to include peripheral cold assessment, which was found to be consistent with subject behavior and measured low T_toe.     

恒温下大戟长管蚜的发育起点温度和有效积温

在16,19,22,25,28和31℃恒温条件下以花卉一串红(Salvia splendens)饲养大戟长管蚜Macrosiphum euphorbiae(Thomas),测得该蚜虫的各龄历期和产仔前期,得出全若虫期的历期。依据有效积温法则计算的1～4龄若蚜和全若虫期的发育起点分别是12.5,7.8,10.3,4.1和9.3℃,有效积温分别是14.6,43.9,29.9,31.9和117.2日.度。大戟长管蚜适合生长发育的温度是19～28℃,最适合温度为25℃。     

Considerations for the measurement of core,skin and mean body temperatures

Despite previous reviews and commentaries, significant misconceptions remain concerning deep-body (core) and skin temperature measurement in humans. Therefore, the authors have assembled the pertinent Laws of Thermodynamics and other first principles that govern physical and physiological heat exchanges. The resulting review is aimed at providing theoretical and empirical justifications for collecting and interpreting these data. The primary emphasis is upon deep-body temperatures, with discussions of intramuscular, subcutaneous, transcutaneous and skin temperatures included. These are all turnover indices resulting from variations in local metabolism, tissue conduction and blood flow. Consequently, inter-site differences and similarities may have no mechanistic relationship unless those sites have similar metabolic rates, are in close proximity and are perfused by the same blood vessels. Therefore, it is proposed that a gold standard deep-body temperature does not exist. Instead, the validity of each measurement must be evaluated relative to one's research objectives, whilst satisfying equilibration and positioning requirements. When using thermometric computations of heat storage, the establishment of steady-state conditions is essential, but for clinically relevant states, targeted temperature monitoring becomes paramount. However, when investigating temperature regulation, the response characteristics of each temperature measurement must match the forcing function applied during experimentation. Thus, during dynamic phases, deep-body temperatures must be measured from sites that track temperature changes in the central blood volume.     

A study of human skin and surface temperatures in stable and unstable thermal environments

Skin temperature is a common physiological parameter that reflects human thermal responses. The purpose of this research was to investigate the effects of radiant temperature on human skin temperature and surface temperature in stable and unstable thermal environments. For a clothed human body, the skin temperature is the surface temperature of the skin, while the surface temperature is the outer surface temperature of the clothes. For this aim, the radiant temperature from 26 to 38 °C and then from 38 to 26 °C was controlled in three different ways; in stable condition keeping stable above 40 min, in unstable condition at a rate of 2 °C/5 min, and in another unstable condition at a rate of 2 °C/10 min. Experimental data showed that at the same radiant temperature, the local skin/surface temperatures during the radiant temperature decrease were higher compared to those during the radiant temperature increase. During the radiant temperature increase/decrease, the increments/decrements of the mean skin temperature and the mean surface temperature decreased gradually from the stable condition, 2 °C/10 min to 2 °C/5 min. Compared to surface temperature, the faster the radiant temperature changed, the more obviously the change in skin temperature was delayed. These data demonstrated that the human body has physiological adaptability to unstable thermal environments.     

Development of a self-contained,indwelling vaginal temperature probe for use in cattle research

A device was developed to monitor the vaginal temperature of cattle in a research setting. This device decreases labor involved with monitoring body temperature compared with manual temperature readings, allows for continuous monitoring of vaginal temperature at 1 min intervals, and also allows for temperature measurements without the presence of a human handler or without restraint, which can agitate cattle. The device consists of a blank controlled internal drug release (CIDR) device (designed by Pfizer Animal Health as an indwelling vaginal probe) that holds an indwelling vaginal temperature probe logger. The fabrication of the vaginal probe costs approximately US $325 per unit. Similar rectal and vaginal temperature responses to lipopolysaccharide challenge were observed when vaginal and rectal temperatures were measured simultaneously in the same heifer (P>0.05). Additionally, rectal and vaginal temperatures were highly correlated (r=0.97; P<0.0001). Similar to the rectal temperature monitoring device, the vaginal device allows for the measurement of vaginal temperature without the potential biases associated with the stress response produced as a reaction to the handling by and (or) presence of humans. The vaginal temperature recording device will provide researchers with an additional inexpensive tool to study physiological responses in female cattle.