基于侧柏液流的测定对Granier原始公式系数进行校正

为研究Granier原始公式计算单株树木蒸腾耗水量的准确性,以侧柏作为研究对象,采用热消散方法测定在15、30、50、70和90cm水柱高度形成不同压力梯度下的树干液流通量密度,并以称重法作为对照,利用回归分析方法拟合称重法测定的液流通量密度与热消散法测定的树干液流温差系数(K值),进而建立校正公式.结果表明:基于侧柏校正的Granier公式为Fd=0.0115K0.5581(R2=0.8319).与称重法测定的液流通量密度相比,校正的Granier公式计算的结果略高(6.70±0.02)％,而Granier原始公式计算的则低估(78.53±0.04)％.由此可知,采用校正的Granier公式计算侧柏的液流通量密度具有较高的精度.     

热消散探针在粉单竹液流研究中的应用

通过对计算树干液流密度的Granier经验公式进行试验验证和校正,比较不同长度的热消散探针(TDP)测量粉单竹液流的结果,探讨TDP在粉单竹液流研究中的适用性,并与邻近生长的常见树种荷木的液流日变化进行比较分析.结果表明:由于粉单竹的竹壁较薄、解剖结构异质性较高,10 mm探针可能低估粉单竹的液流密度,8和5 mm探针监测的液流密度值较准确.粉单竹液流密度平均值和日变化格局的偏度均大于荷木,而夜间荷木的液流活动比粉单竹活跃,说明粉单竹的夜间补水不如荷木.以TDP探针研究竹子的液流是可行的,但应用于不同竹种之前,必须对Granier经验公式进行有效的验证和校正.     

应用Granier热消散探针(TDP)法测定树木的木质部液流:理论与实践

Granier热消散探针法是目前研究树木生理生态和森林水文最常用的测定整树水分利用的方法之一.然而,已有的相关综述文献中,还没有专门介绍利用Granier热消散探针研究木质部液流的综述文章.本文重点介绍了Granier热消散探针测定系统的理论基础,对有关该探针的校准和改进的最新研究进展进行了综述,并还深入探讨了零液流信号值的确定、自然热梯度、损伤效应、液流的逆格型和将木质部液流密度外推至整树蒸腾耗水量等重要的实际问题.     

应用Granier热消散探针（TDP）法测定树木的木质部液流：理论与实践

Granier热消散探针法是目前研究树木生理生态和森林水文最常用的测定整树水分利用的方法之一。然而,已有的相关综述文献中,还没有专门介绍利用Granier热消散探针研究木质部液流的综述文章。本文重点介绍了Granier热消散探针测定系统的理论基础,对有关该探针的校准和改进的最新研究进展进行了综述,并还深入探讨了零液流信号值的确定、自然热梯度、损伤效应、液流的逆格型和将木质部液流密度外推至整树蒸腾耗水量等重要的实际问题。     

Granier原始公式计算树干液流速率的适用性分析——以毛白杨为例

热扩散探针(TDP)在林木蒸腾研究中应用极广,其测定数据的计算精度直接影响对林木和林分耗水的精准定量。Granier原始公式(Fd=0.0119K1.231, Fd为液流速率(cm·s–1), K为温差系数)是计算TDP测定数据的标准方法,但其准确性备受质疑。为系统了解Granier原始公式的适用性和明确对其校正的必要性,该研究以毛白杨(Populus tomentosa)为实验材料,采用室内茎段法和整树容器法,针对不同型号的TDP探针评估Granier原始公式的精度,并对比不同方法校正公式的应用效果。与茎段法实测值相比,Granier原始公式计算的液流速率平均低估52.3%–61.4%。通过茎段法和整树容器法得到的校正公式分别为Fd=0.0362K^1.870和F_d=0.0105K^0.976;且一种方法下得到的校正公式,在其他方法条件下应用时存在较大偏差。与Granier原始公式相比,整树容器法校正公式计算的大田生长状态下的7株林木的平均液流速率没有显著变化,但茎段法和其他研究中得到的毛白杨校正公式的计算结果均显著变大。...     

基于整树称重法的Granier经验公式对毛白杨树干液流测定的适用性

为了评估Granier经验公式在树干液流测定中的适用性,以毛白杨为对象,利用热扩散式探针法(TDP)测定树木的液流速率,以整树称重法进行同步测定,对比分析Granier经验公式在毛白杨树干液流测定中是否存在误差,并对整树称重法测定的蒸腾速率与热扩散法测定的温差系数K进行幂指数回归拟合,建立校正的Granier公式。结果表明:与整树称重法测定的蒸腾速率相比,通过Granier经验公式计算的液流速率低估了67.7%;建立了毛白杨的Granier校正公式F_d=0.0135K^0.6952(R²=0.77),校正后Granier公式的计算结果与整树称重法测定的蒸腾速率相比仅降低了3.4%,具有较好的一致性。因此,采用Granier经验公式计算毛白杨树干液流速率需进行校正。     

热消散液流测定系统研究竹子蒸腾的问题和解决思路

旺盛的蒸腾是竹子迅速生长的重要代谢保障,对林区生态系统水循环和水量平衡发挥关键作用,如何准确估测竹林的蒸腾耗水是迫切需要解决的方法难题。目前研究树木水分生理和森林水文广泛采用的热消散液流测定方法(TDP)却少有在竹林中应用,而仅有的几项研究报道由于缺乏严谨的实验验证,结果误差较大而缺少说服力。作者认为,竹壁结构异质性和竹竿中央空腔造成热量的不均匀分布是基于热通量交换的液流测定系统测量竹子蒸腾不准确的主要原因,提出以自行设计的注水变压液流特性测定法和传统的整树容器称重法,验证热消散液流测定系统估测竹子水分利用的适用性。本文还结合竹子的种群结构和无次生生长的特点,提出竹株借助相互连接的地下茎进行水分再分配,异株补偿水力限制,蒸腾主要受年龄而不是竹形大小影响的观点,建议通过分析竹子蒸腾的年龄效应,研究不同种植密度竹林水分利用的变化规律,为竹林生产和集水区水源管理提供有效的林型设计和措施。     

黄土高原油松冠层气孔导度和蒸腾变化特征与模拟

油松是黄土高原重要的造林树种,模拟其冠层气孔导度和蒸腾对区域水量平衡计算和人工林可持续经营具有重要意义。基于2015-2018年TDP （Thermal dissipation probes）方法所测得液流数据,分析了黄土高原地区油松冠层平均气孔导度（g_c）与冠层蒸腾（Tr）的变化特征与影响因素,并采用Penman-Monteith公式和Jarvis型气孔导度模型模拟了其g_c和Tr的变化过程,结果表明：（1）该地区油松g_c和Tr日内变化均呈现单峰型,日均蒸腾耗水量为（1.25±0.57） mm/d,生长季（4-10月）总蒸腾耗水量均值为195.47 mm。（2）g_c的日内变化受太阳辐射（Rad）驱动（偏相关系数为0.65）,当Rad高于300 W/m²时,驱动作用减弱;g_c的日内变化受水汽压亏缺（VPD）控制（偏相关系数为-0.41）,随VPD的增加而降低;g_c的日际变化受土壤水分限制（偏相关系数为0.46）,当根区相对有效含水率（REW）低于0.45时,限制作用明显。（3）结合Penman-Monteith公式与Jarvis型模型能有效模拟黄土高原油松g_c与Tr变化,小时尺度g_c与Tr模拟的纳什效率系数（NSE）分别为0.80和0.78,日尺度Tr模拟的NSE为0.76。     

不同长度热消散探针测定粉单竹(Bambusa chungii)液流的差异分析和原位验证

由于竹壁较薄,测定液流时安装常规长度(20 mm)的TDP探针易穿破竹壁。与木材的热传导不同,暴露于竹腔内的部分上探针的热量以辐射形式消散,加之竹壁水分传导分子的分布不均匀,导致液流密度的测定值不准确。因此,不少学者主张选用较短的探针,然而,对于改短探针的应用缺乏必要的户外原位验证。本文分析自制的5、8和10 mm的TDP探针原位测定粉单竹液流的适用性和理论依据。结果表明:新建立的液流密度公式与Granier原始经验公式的参数α值的差异较大,主要原因是竹腔的储热效应导致上探针周围温度偏高,竹秆水分含量较低,热消散系数(h0)较小,上探针周围的热量囤积致使上下探针的温差较大;此外,探针的安装方式也影响液流密度的测定结果,是导致相同长度探针测定粉单竹液流密度值明显差别的重要因子。本文通过分析探针周围介质的h0的变化,较合理地解释了这些差异的原因。     

不同叶型维西堇菜叶片结构及光合特征比较

为探讨叶片斑纹的光合适应意义,该文选择有斑和无斑两种叶型的维西堇菜(Viola monbeigii)作为研究材料,采用石蜡切片制片和显微镜观察叶片结构及GFS 3000便携式光合测量仪测量光合参数并进行比较。结果表明:(1)两种叶型维西堇菜气孔均为不等型气孔,有斑叶片上、下表皮气孔密度、栅栏组织(PT)厚度、栅栏组织与海绵组织的比值(PT/ST)均显著低于无斑叶片; 而上表皮气孔较大,表现出更适应弱光环境的结构特征。(2)两种叶型维西堇菜暗呼吸速率(R_d)、初始荧光(F_o)、最大荧光产量(F_m)、光化学猝灭系数(q_P)、非光化学猝灭系数(q_N)、PSⅡ最大光化学量子产量(F_v/F_m)、实际光化学反应量子效率(Yield)均无显著差异,有斑植株叶片叶绿素含量、最大净光合速率(P_max)显著低于无斑植株; 有斑叶片表观光合电子传递速率(ETR)在光合有效辐射(PAR)处于400～2 000 μmol·m^-2·s^-1之间时显著低于无斑叶片,无斑植株的光饱和点(LSP)高于有斑植株,而补偿点(LCP)较低。综上认为,无斑植株PAR利用范围较宽,光合适应能力更强,有利于维西堇菜充分利用环境中有限的资源,保障物种生存; 有斑植株具有较适应弱光胁迫的特征,表明叶片斑纹的出现可能是维西堇菜适应林缘弱光环境的一种策略。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.