实生和嫁接槐树的枝梢生长与光合特性

测定槐树实生树和嫁接树叶片的光合光响应特性、比叶重和叶绿素含量及枝梢生长的结果表明,嫁接树枝梢基径和高度增长趋势与实生树一致,但嫁接树一次、二次梢基径和高度增长量均大于实生树。嫁接树的最大净光合速率、光饱和点、比叶重和单位重量的叶绿素含量均显著高于实生树,高的光合能力与其单位面积叶片重量增加和单位重量叶绿素含量增高有关。嫁接槐树的类胡萝卜素与叶绿素比值高于实生槐树,叶绿素a,b比值和单位重量类胡萝卜素含量显著高于实生槐树,表明其对强光的适应性强。     

盐碱地土壤改良对银中杨叶片、树枝和树皮绿色组织色素和C_4光合酶的影响

在松嫩平原重度盐碱地上,选择通过土壤改良使得盐碱成分降低、结构显著改善的土壤作为处理样地(pH值9.17;电导率388μscm-1;土壤紧实度1170kPa),邻近未改良重度盐碱地为对照样地(pH值10.15;电导率1220μscm-1;土壤紧实度2199kPa),对生长在对照和处理样地上的银中杨不同器官叶绿素和C4光合相关酶研究发现:1)生长在处理样地的银中杨叶片叶绿素a+b、叶绿素a/b、类胡萝卜素含量显著高于对照未处理,但树枝和树皮绿色组织内这些指标的差异远小于叶片;2)所测定3种C4光合酶结果显示,当以单位鲜重表示时,3种器官以及盐碱化程度对结果影响较小;3)当以单位叶绿素酶活性表示时,不同器官以及盐碱化程度对酶活性影响显著:树皮和树枝磷酸烯醇式丙酮酸酶(PEPC)活性是叶片的4.4和3.1倍,盐碱地改良使这一差异变成8.6和2.6倍;对照样地内树皮、树枝的苹果酸酶(NADP-ME)活性是叶片的1.7和2.1倍,盐碱地土壤改良使得这一差异达到17.2和6.4倍;与此类似,在对照盐碱地上,树皮和树枝内苹果酸脱氢酶(NADP-MDH)活性是叶片的1.7和1.4倍,盐碱地土壤改良使得这一差异变为6.4和13.7倍。上述结果说明,银中杨树干和树枝绿色组织内C4相关酶含量较叶片高出很多,而且受盐碱胁迫程度影响显著,盐碱化程度轻的情况下,这种差异会增大,这些酶的变化可以作为植物响应土壤盐碱程度变化的一种生理生化指示指标。     

茚虫威对玫瑰三节叶蜂叶绿素和类胡萝卜素含量的影响

【背景】研究昆虫体色不仅在昆虫系统学中,而且在生物学、生态学和害虫防治等中都具有重要意义。有些取食植物叶片的幼虫体色表现为绿色,该绿色是由类胡萝卜素与蓝色四吡咯色素结合所形成,叶绿素又属于四吡咯化合物。但目前尚未见昆虫体内含叶绿素的报道。【方法】在田间套笼饲养玫瑰三节叶蜂幼虫,饲养至5和6龄时,借鉴植物叶绿素测定方法,分别测定其叶绿素含量,并在6龄时用杀虫剂茚虫威处理,观测对其叶绿素含量的影响。【结果】5和6龄玫瑰三节叶蜂幼虫均含有叶绿素,且5龄幼虫含量高于6龄幼虫。其中,5龄幼虫叶绿素a含量为1.6780 mg·g-1,叶绿素b为0.6847 mg·g-1,类胡萝卜素为0.4797 mg·g-1;6龄幼虫叶绿素a含量为1.2726 mg·g-1,叶绿素b为0.5187 mg·g-1,类胡萝卜素为0.4863 mg·g-1。剔除幼虫消化道后,5龄幼虫叶绿素a含量为0.4008 mg·g-1,叶绿素b为0.2618 mg·g-1,类胡萝卜素为0.2444 mg·g-1;6龄幼虫叶绿素a含量为0.4299 mg·g-1,叶绿素b为0.3826 mg·g-1,类胡萝卜素为0.2859 mg·g-1。用茚虫威处理后,6龄幼虫体内叶绿素和类胡萝卜素含量（含消化道）显著下降,其中,叶绿素a下降约48%,叶绿素b下降约34%,类胡萝卜素下降约37%;而对于剔除消化系统的6龄幼虫,茚虫威处理后,其叶绿素和类胡萝卜素含量下降幅度较小。【结论与意义】玫瑰三节叶蜂幼虫含有叶绿素和类胡萝卜素,杀虫剂能降低其叶绿素和类胡萝卜素含量,且其体色可能与叶绿素有着密切的关系。     

遮荫处理对红叶石楠和洒金桃叶珊瑚光合特性的影响

研究不同遮荫处理(透光率分别为20%、40%、60%、100%)对红叶石楠和洒金桃叶珊瑚两种观叶植物光合特性的影响.结果表明：遮荫处理6周后,与遮荫状态下原位测定相比,自然状态下两种植物异位测定的光合作用增强,随着遮荫程度的增强, 叶片净光合速率呈增大趋势, 红叶石楠和洒金桃叶珊瑚的最大值分别为9.7和8.3 μmol·m^-2·s^-1;两种植物的蒸腾速率显著提高.遮荫处理不同程度地提高了两种植物叶片叶绿素a、b含量、叶绿素a+b总量及叶绿素/类胡萝卜素值,降低了叶绿素a/b值,但类胡萝卜素含量无显著变化.在自然状态下,红叶石楠净光合速率和蒸腾速率的表型可塑性指数(PPI)分别为2.08和3.21;洒金桃叶珊瑚的相应指标仅为0.55和1.60.两种植物的叶绿素和类胡萝卜素含量相对稳定,受外界环境因子影响相对较小.洒金桃叶珊瑚的耐荫性高于红叶石楠.     

光胁迫对南方红豆杉叶片中叶绿体色素和紫杉醇含量的影响

研究了在光胁迫下南方红豆杉叶片中叶绿体色素含量和紫杉醇含量的动态变化。结果表明,与对照相比,叶绿素a、叶绿素b和总叶绿素的含量以及叶绿素a/叶绿素b比值在光胁迫下均减少,随胁迫时间的延长,叶绿素a、叶绿素b和总叶绿素的含量逐渐上升,叶绿素a与叶绿素b的比值先上升后下降;类胡萝卜素含量在前两周与对照相比降低,2周后高于对照;类胡萝卜素与叶绿素的比值高于对照,随胁迫时间的延长,其趋势先降低后上升。光胁迫处理后,南方红豆杉叶片中紫杉醇含量与对照相比,在第1周时略有下降,而后随胁迫时间的延长,紫杉醇含量在第2周开始迅速大量积累,而在处理3周时达到较高值,已增加到1.5倍,这对提高人工种植的南方红豆杉中紫杉醇含量具有非常重要的意义。     

互花米草与芦苇光合色素含量对淹水措施的响应

以上海崇明东滩入侵植物互花米草与本地种芦苇为研究对象,研究持续淹水胁迫对两种植物光合色素含量的影响.结果表明：互花米草与芦苇叶片的光合色素基本组成与含量不同,对持续淹水的响应也不同.在持续淹水胁迫下,互花米草叶绿素a、叶绿素b及类胡萝卜素含量降低,叶绿素a／b、类胡萝卜素／叶绿素值提高;芦苇各色素含量升高,叶绿素a／b、类胡萝卜素/叶绿素值基本保持稳定.解除持续淹水胁迫后,互花米草各色素含量逐渐升高,叶绿素a／b、类胡萝卜素／叶绿素值降低,并逐渐接近对照水平;而芦苇各色素含量显著高于对照.两种植物均表现出一定的补偿效应,但芦苇比互花米草更能适应同等程度的持续淹水胁迫.应用持续淹水措施治理互花米草时,可采用本地种芦苇作为治理后湿地恢复的替代植物.     

格木幼苗对硝普钠-酸铝互作的生理响应

以格木（Erythrophleum fordii Oliv.）幼苗为材料,采用双因素完全随机设计实验方法,测定不同处理幼苗的光合色素和可溶性糖等生理指标,研究格木幼苗对硝普钠（SNP）-氯化铝（AlCl₃）互作的生理响应。结果显示,格木幼苗叶片中叶绿素a、叶绿素b和类胡萝卜素含量均在处理4（0.2 mmol/L AlCl₃、0.1 mmol/L SNP）时最高,在处理9（0.8 mmol/L AlCl₃、0 mmol/L SNP）时含量最低,而叶片中丙二醛（MDA）、游离脯氨酸含量则相反;叶片可溶性糖、可溶性蛋白含量在处理4时最高,在处理9时最低;处理10（0.8 mmol/L AlCl₃、0.1 mmol/L SNP）的超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性最高。施加SNP后,格木幼苗叶片中的叶绿素a、叶绿素b、类胡萝卜素、可溶性糖、可溶性蛋白含量及SOD、POD、CAT活性均显著高于未施加SNP处理。相关性分析表明,叶绿素a、类胡萝卜素、总叶绿素和可溶性蛋白含量等指标间均呈极显著正相关（P < 0.01）。本研究结果得出,低浓度AlCl₃（0.2 mmol/L）胁迫可促进格木幼苗的生长,添加外源SNP对高浓度AlCl₃（0.8 mmol/L）胁迫格木幼苗产生的毒害具有一定的缓解作用,可在格木幼苗的培育及抗性研究中推广应用。     

沙木蓼和沙枣对地下水位变化的生理生态响应Ⅰ.叶片养分、叶绿素、可溶性糖和淀粉的变化

在甘肃民勤沙生植物园内利用植物蒸腾耗水量观测场,研究了两种优势旱生植物沙木蓼（Atraphaxis frutescens)和沙棘（Elaeagnus angustifolia)叶片中的叶绿素、可溶性糖,淀粉和N、P、K、含量等对不同地下水深度（1－3．4m）的响应。结果表明：1）1.4m,2.4m和3．4m 3种不同地的地下水深度处理,产生了3种差异显著的土壤水分梯度;2）地下水深度的变化导致了这两种旱生植物叶绿素a、叶绿素b、叶绿素总量、叶绿素a与叶绿素b的比值等的显著变化（P＜0．01）;3）地下水深度的增加引起了两种植物叶片可溶性糖含量的升高和淀粉含量的降低;4）地下水深度的增加引起了两种植物叶片中N、P、K含量的降低;5）不同的地下水深度引起沙棘和沙木蓼叶绿素a、叶绿素b、叶绿素总量、叶绿素a与叶绿素b的比值、N、P、K含量,可溶性糖和淀粉增加或减少的程度不同。沙棘是非豆科固氮植物,两者的差异是否与固氮作用相关还有待于进一步研究。     

福建梅花山57种常绿树叶片叶绿素特征分析

选取福建梅花山海拔1200m和455m地区57种常绿植物为研究对象,测定两海拔的植物叶片叶绿素a和叶绿素b含量,并计算叶绿素a/b、总叶绿素含量。结果表明:(1)植物叶绿素a、b,叶绿素a+b及叶绿素a/b值大多分布在一个相对集中的区域。(2)多数植物新叶叶绿素含量高于老叶,叶绿素a/b值低于老叶,但是新、老叶无显著差异。(3)不同海拔的植物叶片总叶绿素含量和叶绿素a/b值有明显差异,低海拔地区明显高于高海拔地区。植物通过总叶绿素含量和a/b值的变化以适应不同环境条件。     

3种C3木本植物绿色组织C4酶活性、色素含量及叶绿素荧光参数的比较

对3种C₃木本植物丁香（Syringa meyeri）、杨树（Populus alba）、落叶松（Larix gmelinii）叶片和树枝绿色组织相关指标分析发现：3种植物叶片Chl.a+b含量均显著高于树枝,但是树枝较叶片Chl.a/b比值差异不明显（丁香、落叶松）（p>0.05）或显著高（杨树）(p<0.05)。单位叶绿素内各酶活性显示,丁香树枝PEPC、PEPCK、PPDK、NADP-ME、NADP-MDH酶活性分别是叶片的2.4、4.1、3.2、4.5和1.9倍;杨树树枝分别是叶片的2.1、15、6.3、6.3和2.8;落叶松树枝分别是叶片的6.8、6.3、4.3、4和5.5倍,而单位鲜重内各酶活性显示出的树枝与叶片的差异均小于单位叶绿素的相应结果。种间比较发现,杨树叶片和树枝5种酶活性均显著高于丁香和落叶松。树枝绿色组织内C₄酶活性普遍高于相应叶片的事实说明,木质化绿色组织内可能存在C₄酶相关的生化过程。丁香与落叶松树枝的电子传递速率、PSⅡ效率大于叶片,杨树叶片的相应值大于树枝,相关分析表明,这种高的C₄酶活性并没有显著影响叶绿素荧光参数（p>0.05）,显示出树枝绿色组织和C₃植物叶片内C₄酶对光合影响的复杂性。     

Energy Transfer among Chlorophylls in Trimeric Light-harvesting ComplexⅡ of Bryopsis corticulans

A study on energy transfer among chlorophylls(Chls)in the trimeric unit of the major light-harvesting complex Ⅱ(LHC Ⅱ)from Bryopsis corriculan,was carried out using time-correlated singlephoton counting.In the chlorophyll Q region of LHC Ⅱ,six molecules characterized as Chlb_(628),Chlb_(646),Chlb_(652)~(654,657),Chla_(664)~(666),Chla_(674)~(677.680)and Chla_(682)~(683) were discriminated according to their absorption spectrumand fluorescence emission spectrum.Then,excited by pulsed light of 628 nm,fluorescence kinetics spectrain the chlorophyll Q region were measured.In accordance with the principles of fluorescence kinetics,thesekinetics data were analyzed with a multi-exponential model.Time constants on energy transfer were obtained.An overwhelming percentage of energy transfer among chlorophylls undergoes a process longer than 97picoseconds(ps),which shows that,before transferring energy to another Chl,the excited Chl might convertenergy to vibrations of a lower state with different multiplicity(intersystem crossing).Energy transfer at thelevel of approximately 10 ps was also obtained,which was interpreted as the excited Chls may go throughinternal conversion before transferring energy to another Chl.Although with a higher standard deviation,timeconstants at the femtosecond level can not be entirely excluded,which can be attributed to the ultrafastprocess of direct energy transfer.Owing to the arrangement and direction of the dipole moment of Chls inLHC Ⅱ,the probability of these processes is different.The fluorescence lifetimes of Chlb_(652)~(654,657),Chla_(664)~(666),Chla_(674)~(677.680)and Chla_(682)~(683)were determined to be 1.44ns,1.43 ns,636 ps and 713 ps,respectively.Thepercentages of energy dissipation in the pathway of fluorescence emission were no more than 40% in thetrimeric unit of LHC Ⅱ.These results are important for a better understanding of the relationship between thestructure and function of LHC Ⅱ.     

Leaf senescence in a non-yellowing mutant of Festuca pratensis: Degradation of carotenoids

The loss of pigments was assessed in detached leaves of Festuca pratensis Huds. kept in permanent darkness. Two genotypes, a normal yellowing cultivar Rossa and a non-yellowing mutant Bf 993 were compared with each other. Analysis of individual pigments, chlorophylls. β-carotene, lutein, violaxanthin and neoxanthin was performed using HPLC. In the non-yellowing genotype the high retention of chlorophylls was associated with an equally high retention of total carotenoids. Although the two genotypes differ markedly with regard to the rate of pigment loss, the ratios of yellow to green pigments did not change significantly during dark-induced senescence. At the end of the senescence period β-carotene was retained to a higher degree than the xanthophylls, particularly in the yellowing genotype. In the mutant leaves the ratio of chlorophyll a to b remained nearly constant, whereas in leaves of the normal genotype a preferential retention of chlorophyll b was observed towards the end of the senescence period. It is concluded that the thylakoids of the non-yellowing genotype retain all the principal components of protein-pigment complexes, i.e. chlorophylls, carotenoids and apoproteins. Possible explanations for the stability of these complexes in the mutant are discussed.     

Are Bryophytes Shade Plants? Photosynthetic Light Responses and Proportions of Chlorophyll a,Chlorophyll b and Total Carotenoids

BACKGROUND AND AIMS: Data are presented from 39 species of mosses and 16 liverworts for ratios of chlorophylls and total carotenoids, and light saturation of photosynthetic electron flow or photosynthetic CO2 uptake, in relation to the postulate that bryophyte cells in general show shade-plant characteristics. METHODS: Pigment concentrations were measured by spectrophotometer in 80 % acetone extracts. Light-saturation curves were constructed by (modulated) chlorophyll florescence and for some species by infra-red gas analysis. KEY RESULTS: The pigment measurements were widely variable but broadly in line with the findings of previous authors. Median values (mosses/liverworts) were: total chlorophyll, 1.64/3.76 mg g(-1); chlorophyll a : b, 2.29/1.99; chlorophylls : carotenoids, 4.74/6.75). The PPFD values at 95 % saturation (estimated from fitted curves) also ranged widely, but were almost all <1000 micromol m(-2) s(-1); the median for mosses was 583 and for liverworts 214 micromol m(-2) s(-1). The two highest PPFD95% values were from Polytrichum species with lamella systems forming a ventilated photosynthetic tissue. Total chlorophyll, chlorophyll a : b and chlorophylls : carotenoids all correlated significantly with PPFD95%. CONCLUSIONS: Bryophytes include but are not inherently shade plants. Light-saturation levels for species of open sun-exposed habitats are lower than for vascular sun plants and are probably limited by CO2 diffusion into unistratose leaves; this limit can only be exceeded by bryophytes with ventilated photosynthetic tissues which provide increased area for CO2 uptake.     

模拟酸雨对龙眼叶绿体活性的影响

研究了模拟酸雨对龙眼叶绿体活性的影响,结果表明,pH≤3．5的酸雨胁迫使用叶绿素（Chl),类胡萝卜素（Car)含量下降,Chl含量的下降是Chla含量下降的结果,Chlb对酸雨的反应不敏感,因而Chla/Chlb下降,Chl和Car含量,Chla/Chlb随胁迫时间的延长而下降,光照加剧了酸雨对光合色素的伤害,酸雨胁迫使叶绿体光还原活性,光合磷酸化活性,H^ -ATPase活性降低,电子传递链的破坏与磷酸化解偶联,从而使叶绿体不能有效吸收,传递,转换光能,光合磷酸化过程对酸雨胁迫的反应比光还原过程敏感。     

Factors affecting the accuracy of chlorophylla andb determination by means of their paper chromatographic separation and colorimetric measurement in eluates

Quantitative determination of chlorophyll a and β can be made by paper chromatography of acetone extracts of plant material with colorimetric measurement of the eluates from the separated zones. From the suitable solvent systems which give adequate separation of the pigments at a distance of 20 cm. from the start,Hager's mixture (1955) separates the chlorophylls better than the toluene-isopropanol (400: 1 v/v.) mixture, which, however, is better for the separation of carotenoids. Twice the amount of chlorophyll is separated on Whatman 31 ET paper, equally well and with the same time of development, as on Whatman No. 3 paper, on which it is possible to separate a maximum of about 15 μg of chlorophyll pigments per 1 em. start length. Losses on elution are, however, higher on using Whatman 31 ET paper. In plants with a high chlorophyllase activity, the error of determining chlorophyll a andb is greatly reduced if the leaves are placed for 1 min. in boiling water before extraction. For elution of chlorophylla andb from paper it is better to use anhydrous acetone, for chlorophyllides 80% acetone. A comparison of the procedure investigated with the method of two-wave length spectrophotometric measurement of crude acetone extracts showed that in view of the average 10% loss, the chromatographic method is hardly suitable for determining the absolute amounts of chlorophylla andb, although the relation (a/b) can be determined with similar precision by both methods. Moreover, in view of the greater amount of work involved the chromatographic method can only be recommended for confirming the results of spectrophotometrie determination. Quantitative determination of chlorophylls from the area of the spot or from the "R_F" value can only be of an informative character.     

Separation and quantification of pigments from natural phototrophic microbial populations

Abstract A simple high-performance liquid chromatography (HPLC) method is described for the rapid (approx. 20 min) simultaneous separation and identification of the major chlorophylls and carotenoids from phytoplankton cells and phototrophic sulfur bacteria. Lyophilized samples were extracted with acetone in the dark at room temperature. Pigments were eluted from a silica column with a hexane-acetone mixture (80: 20, v/v). About 20 algal and bacterial chlorophyll and carotenoid pigments could be separated in one run. The method allowed for the detection of trace amounts of major carotenoids (> approx. 6 ng · 1⁻¹) and of chlorophylls and pheophytins (> approx. 200 ng · 1⁻¹) in natural samples. The method has been applied to samples from the metalimnion of Lake Vechten (The Netherlands) and has proved very useful in estimating algal and bacterial pigments simultaneously with respect to depth distribution and biomass changes of the microbial populations.     

Site-directed photochemical coupling of cytochrome b6f-associated chlorophyll

Cytochrome b(6)f complexes contain a molecule of chlorophyll a (Chla), which, in Chlamydomonas reinhardtii, can be exchanged for extraneous chlorophyll during protracted incubation of the purified complex in detergent solution. The specificity of the site and its location in the complex have been studied by photochemical coupling and circular dichroism spectroscopy. Following substitution of the original chlorophyll with [(3)H]Chla, the complex was irradiated in the Soret absorption band of Chla to complete bleaching and the amount of radioactivity covalently bound to each b(6)f subunit determined. Strong labeling was found to be associated with cytochrome f. The labeling originates from [(3)H]Chla molecules bound to a slowly exchanging site and showing the properties of the endogenous Chl, not from molecules dissolved in the detergent belt surrounding the complex. Chlorophyll b (Chlb) can compete with Chla, albeit with a lower affinity. Irradiation of [(3)H]Chlb introduced into the slowly exchanging site yielded the same labeling pattern that was observed with [(3)H]Chla. Proteolytic cleavage showed [(3)H]Chla labeling to be strictly restricted to the C-terminal region of cytochrome f. Circular dichroism spectra of the native complex revealed a bilobed signal characteristic of excitonic interaction between chlorophylls. The structural and evolutionary implications of these findings are discussed.     

Effects of Light Quality and Norflurazon on the Formation of Plastid Pigments in Cotyledons of Pinus sylvestris

The effects of different light qualities and a special inhibitor of carotenoid biosynthesis on formation of plastid pigments of cotyledons of Pinus sylvestris were studied. The experimental results indicate: 1. The rate of synthesis of carotenoids in far-red light is relatively higher than that of chlorophylls, on the contrary in red light the rate of chlorophyll synthesis is higher. 2. When biosynthesis of carotenoids is inhibited, in white light the rate of total chlorophyll synthesis reduced with similar proportion. Accumulation of chlorophyll, however, is relatively much more than that of carotenoids. The highest molar ratio of chlorophyll/carotenoids is approximately 10.0. This implicates that chlorophyll and carotenoid synthesis proceed with certain independence. 3. After 4h exposure of strong white light of 9 day-old pine seedlings grown with 10-5 mol 1-1 norflurazon in farred light, contents of carotenoids and total, chlorophyll of cotyledons increase. Chlorophyll a biosynthesis promoted by light is higher than photooxidation of the pigment.     

Changes in the chlorophyll and carotenoid contents in the leaves of steppe plants along a latitudinal gradient in South Ural

We studied the content of chlorophylls and carotenoids in the leaves of steppe plants of South Ural growing along a latitudinal gradient from southern steppe to forest-steppe. The content of chlorophylls (a + b) was 5–6 mg per 1 g of the leaf dry weight and did not depend on the latitude, whereas the content of carotenoids in the leaves increased northward from 1.0 to 1.5 mg/g dry wt. At the same time, the greatest changes occurred in the ratios between the forms of pigments: the chlorophyll a/b ratio increased from 1.8 to 2.8, and the chlorophyll/carotenoid ratio decreased from 5.6 to 3.5. The obtained results indicate that adaptation of the pigment apparatus of steppe plants growing along the latitudinal gradient occurs due to the transformation of the light-harvesting complex.