茶叶儿茶素总量比色测定的盐酸(硫酸)香草醛显色反应能力评价

测定了茶叶儿茶素及绿茶、红茶中的儿茶素与盐酸(硫酸)-香草醛的显色反应水平,通过对反应系数、准确度、精密度测定和比较,评价了儿茶素与酸性香草醛的显色反应能力。结果表明:两种酸性体系对儿茶素反应灵敏,且呈高度线性相关(R2盐酸=0.997 6±0.001 4,R2硫酸=0.997 8±0.001 8);显色反应系数上,盐酸法为34.77±10.00(绿茶)、83.83±20.13(红茶);硫酸法为39.65±8.97(绿茶)、86.68±19.87(红茶),均低于茶叶儿茶素总量经验计算公式中Roberts系数(145.68)。盐酸-香草醛显色反应体系的回收率为94.22%±3.33%(绿茶)、99.71%±1.39%(红茶),精密度的变异系数为0.08%(绿茶)、0.07%(红茶);硫酸-香草醛显色反应体系的回收率为95.78%±1.95%(绿茶)、99.95%±2.56%(红茶),精密度的变异系数为0.07%(绿茶)、0.06%(红茶),表明两种体系均能测定茶叶儿茶素总量。来源于不同茶类、等级茶的儿茶素类与酸性香草醛的显色能力差异极显著(F=37.434>F0.01[1,5]=6.61),说明两种反应体系均能客观表征茶叶儿茶素总量。由经验公式计算法得到的回收率(绿茶120.59%±34.86%,红茶114.09%±0.20%)和变异系数(绿茶28.91%,红茶0.17%)均不稳定,且其测定的儿茶素总量也偏高于实际值。     

Synergetic deodorant effect and antibacterial activity of composite paper containing waste tea leaves

Composite paper containing waste tea leaves was prepared to investigate the effective utilization of waste tea leaves as deodorant material. Paper containing waste green tea leaves did not have increased deodorizing ability compared with controls either against acidic odors such as hydrogen sulfide and acetic acid gases or against neutral odors such as formaldehyde and acetaldehyde gases. In contrast, the paper had excellent deodorizing ability against basic odors such as ammonia and trimethylamine gases. It was observed during additional tests conducted on paper samples containing 60 wt% waste leaves of oolong tea, black tea, pu-erh tea, or hojicha, that all the samples reduced the ammonia concentration to below 1 ppm, which is the threshold concentration for olfactory recognition, within 30 min. Further, paper containing waste green tea leaves was found to decrease the odor residual rate to 5.1% in 30 min even for a waste tea leaf content of 10 wt%. The excellent deodorizing ability of the paper could be attributed to the chemical reactions between odorous substances and the catechins found in tea leaves. After the deodorization of ammonia, paper containing waste green tea leaves was found to have increased antibacterial activity against Staphylococcus aureus.     

Improving the antibacterial activity against Staphylococcus aureus of composite sheets containing wasted tea leaves by roasting

We used various kinds of wasted tea leaves to develop composite sheets with antibacterial properties. Antibacterial tests showed that the number of viable bacterial cells for the sheet containing wasted green tea leaves was around 10:⁶–10⁷ CFU/ml after 18 h culture compared to 108 CFU/ml for a tea-free sheet. This indicates that cell growth was signifi cantly inhibited. For sheets containing other types of tea leaves (oolong, black, hojicha, and pu-erh), living cells were not found, indicating that these sheets had superior antibacterial effects. Living cells were also not found in sheets containing wasted black tea leaves or roasted tea leaves at a concentration of 60% by weight after 6 h cultivation. Therefore, roasting treatment of wasted green tea leaves was examined to improve the antibacterial activity of the sheet. In particular, the focus was on structural conversion of catechins by heating.     

Reactivity of green tea catechins with formaldehyde

In the reaction of green tea catechins with formaldehyde at room temperature (25°C), tea catechins were found to have reactivity. In particular, (-)-epicatechin gallate and (-)-epigallocatechin gallate, which have a galloyl moiety at the C-3 position, showed higher reactivity than (+)-catechin, (-)-epicatechin, or (-)-epigallocatechin. Reactivity of various kinds of simple phenolic compounds and flavonoids with formaldehyde was also examined. Among these compounds, only phloroglucinol showed reactivity to the same degree as that of nongalloylated catechins. These results suggest that factors for reactivity with formaldehyde at room temperature may be the presence of a phloroglucinolic A-ring structure and the absence of the electron-attractive group such as a carbonyl group in Cring. The comparison of the reactivity of 3-O-acylated catechins with that of 3-O-galloylated catechins indicated that only a galloyl group effectively enhanced reactivity with formaldehyde.     

Photosynthetic capacity in relation to nitrogen in the canopy of a Quercus robur, Fraxinus angustifolia and Tilia cordata flood plain forest

We measured gas exchange and various leaf parameters of ash (Fraxinus angustifolia Vahl.) and oak (Quercus robur L.) in the high canopy and of lime (Tilia cordata Mill.) in the lower canopy of a planted, 120-year-old floodplain forest in southern Moravia, Czech Republic. The high-canopy leaves of F. angustifolia and Q. robur had nitrogen concentrations on a leaf area basis (N(area)) that were twice those of low-canopy leaves of T. cordata. Upper-canopy leaves of F. angustifolia had a photosynthetic rate at light saturation (A(max)) of about 16 micromol CO2 m(-2) s(-1), whereas A(max) of the upper-canopy foliage of Q. robur achieved only about two thirds of this value. Contrary to previous investigations of photosynthetic performance in monospecific stands, leaves of the uppermost branches of T. cordata at 15-m height had the highest A(max) and transpiration rate among the species studied. Water-use efficiency (WUE) was low in T. cordata at 15-m canopy height, whereas WUE was significantly higher for Q. robur leaves at 27-m height than for the other species. Leaves of T. cordata at 15-m height showed the strongest relationship between A(max) and N(area) (R2 = 0.90) followed by F. angustifolia (R2 = 0.69). The strong correlation between photosynthesis and nitrogen concentration in T. cordata at 15 m, together with the steep regression slope for the A(max):N(area) relationship, indicated that nitrogen allocation to the photosynthetic apparatus resulted in high nitrogen-use efficiency of light-saturated photosynthesis (PNUE). Despite differences in PNUE among species, PNUE was fairly constant for leaves sampled from the same canopy position, suggesting that single-leaf parameters are matched to optimize PNUE for prevailing light conditions. High PNUE in T. cordata at 15 m partially compensated for the species' subordinate position in the canopy, and may be an important mechanism for its coexistence in highly structured vegetation.     

锰对苦丁茶化学品质的影响

为探讨锰对苦丁茶化学品质的影响,采用国际通用的营养液配方对苦丁茶进行砂培盆栽试验。结果表明：MnCl2·4H2O对苦丁茶叶片中游离氨基酸、可溶性蛋白、维生素C等含量的提高非常有利。锰处理苦丁茶30 d后,上述各物质含量均随着锰质量浓度的增加呈先增加后降低的变化,而锰和皂苷则随着质量浓度的增加而增加。MnCl2·4H2O质量浓度为6.0 mg/L时,苦丁茶叶片中可溶性蛋白、维生素C、黄酮及茶多酚含量最高,此质量浓度对提高这几种化学物质含量较好;MnCl2·4H2O质量浓度为8.0 mg/L时,苦丁茶叶片中锰和皂苷含量最高,分别为0.555μg/g和0.828 mg/g。酚氨比随着锰质量浓度的增加先增加后降低。以MnCl2·4H2O质量浓度为6.0mg/L时茶多酚、黄酮、游离氨基酸和可溶性蛋白含量最高,品质良好,开发利用价值相对较好。     

"湘妃翠"鲜叶与成品茶主要品质成分的季节变化

采用氨基酸自动分析仪、高效液相色谱和茶叶国标检测方法测定分析了不同季节“湘妃翠”鲜叶及其成品茶中游离氨基酸、儿茶素、咖啡碱、茶多酚和水浸出物的含量。结果表明:鲜叶与成品茶中游离氨基酸、儿茶素、咖啡碱、茶多酚和水浸出物含量等的品质成分的季节变化明显,趋势一致,春季明显优于夏秋季、秋季优子夏季;与鲜叶的品质成分状况相比,成品茶的品质成分状况明显改善,奠定了感官品质的生化基础。根据分析结果提出了“湘妃翠”品种在夏秋季生产普通绿茶而不生产名优茶的建议。     

Effects of NO3- availability on NO3- use in seedlings of three woody shrub species

We determined the effects of short-term cultivation with various amounts of available nitrate nitrogen (NO3-) on NO3- use by woody shrub species. Nitrate concentration ([NO3-]) and nitrate reductase activity (NRA) were measured in leaves and roots of seedlings of Hydrangea hirta (Thunb.) Siebold, Lindera triloba (Sieb. et Zucc.) Blume and Pieris japonica (Thunb.) D. Don. Root [NO3-] increased with increasing NO3- supply in all species, whereas leaf [NO3-] remained low. There were significant correlations between [NO3-] in roots and leaves in all species, but no correlation was found between root NRA and leaf NRA. The low proportion of leaf NO3- assimilation to total NO3- assimilation in all species can be ascribed to the lack of NO3- transport from roots to leaves. In all species, root NRA increased with increasing NO3- supply until reaching a plateau. Species ranking based on maximum root NRA was H. hirta > L. triloba > P. japonica. Root NRA in P. japonica was low, even though root [NO3-] increased with NO3- supply, indicating that NO3- was not an effective N source for this species. The ranking also suggested that H. hirta depended more on NO3- as an N source than L. triloba. The increase in root NRA with increasing NO3- supply was greater in H. hirta than in L. triloba, possibly indicating that a change in NO3- availability has a stronger influence on NO3- use in H. hirta than in L. triloba.     

不同品种茶叶的抗癌活性研究

本研究应用分光光度法和高效液相色谱法测定了4种不同茶叶的化学成分和儿茶素的含量,结果表明,茶叶品种不同,其化学成分、儿茶素的组成与配比差异较大,这是决定其抗癌作用的物质基础。     

Neutralization and buffering capacity of leaves of sugar maple, largetooth aspen, paper birch and balsam fir

We compared the acidity, the external acid neutralizing capacity and the buffering capacity of leaves of four commercially important tree species, largetooth aspen (Populus grandidentata Michx.), sugar maple (Acer saccharum Marsh.), paper birch (Betula papyrifera Marsh.) and balsam fir (Abies balsamea (L.) Mill), at two sites of contrasting soil fertility in southern Quebec. External acid neutralizing capacity (ENC) of leaves was determined by measuring the change in pH induced by soaking fresh leaves in an acidic solution (pH 4.0) for two hours. The ENC was highest for largetooth aspen (14.3 micro equiv H(+) g(-1)), and lowest for sugar maple and balsam fir (< 5 micro equiv H(+) g(-1)). The buffering capacity index (BCI) was determined by measuring the amount of acid necessary to produce a change of 5 micro equiv H(+) in the leaf homogenate. The BCI ranged from 883 micro equiv H(+) g(-1) for largetooth aspen to less than 105 micro equiv H(+) g(-1) for sugar maple and balsam fir. Leaves of sugar maple and balsam fir had a lower internal pH and a higher percentage of ENC over BCI than paper birch and largetooth aspen. Overall, ENC was correlated with the concentration of all leaf nutrients except Ca, and BCI was correlated with Mg, N and Ca. The site effect was relatively unimportant for all variables.     

Interspecific variability of stem photosynthesis among tree species

The photosynthetic characteristics of current-year stems of six deciduous tree species, two evergreen tree species and ginkgo (Ginkgo biloba L.) were compared. Gas exchange, chlorophyll concentration, nitrogen concentration and maximum quantum yield of PSII were measured in stems in summer and winter. A light-induced decrease in stem CO(2) efflux was observed in all species. The apparent gross photosynthetic rate in saturating light ranged from 0.72 micromol m(-2 )s(-1) (ginkgo, in winter) to 3.73 micromol m(-2) s(-1) (Alnus glutinosa (L.) Gaertn., in summer). Despite this variability, a unique correlation (slope = 0.75), based on our results and those reported in the literature, was found between gross photosynthetic rate and dark respiration rate. Mass-based gross photosynthetic rate decreased with stem mass per area and correlated to chlorophyll concentration and nitrogen concentration, both in summer and winter. The radial distribution of stem chlorophyll differed among species, but all species except ginkgo had chlorophyll as deep as the pith. In summer, the maximum quantum yield of stem PSII (estimated from the ratio of variable to maximal fluorescence; F (v)/F (m)) of all species was near the optimal value found for leaves. By contrast, the values were highly variable in winter, suggesting large differences in sensitivity to low-temperature photoinhibition. The winter values of Fv/Fm were only 31-60% of summer values for the deciduous species, whereas the evergreen conifer species maintained high F (v)/F (m) in winter. The results highlight the interspecific variability of gross photosynthesis in the stem and its correlation with structural traits like those found for leaves. The structural correlations suggest that the selection of photosynthetic traits has operated under similar constraints in stems and leaves.     

Importance of weed control, fertilization, irrigation, and genetics in slash and loblolly pine early growth on poorly drained spodosols

Research reported here has evaluated interactions of factors limiting the biological potential of slash pine (Pinus elliottii var. elliottii Engelm.) and loblolly pine (P. Taeda L.). Water and nutrients were manipulated by irrigation, weed control, and intensive fertilization. Genetic factors were incorporated as (1) improved loblolly seedlings from a commercial clonal seed orchard and (2) slash seedlings from four fast-growing, open-pollinated seed-orchard clones. Three replications of a 2 × 2 × 2 factorial experiment were established on a Typic Haplaquod soil in northern Florida using four cultural treatments: no treatment (F0H0); weed control (F0H1); fertilizer (F1F0); and combination of weed control and fertilizer (F1H1) for each species. During the first year there were large, sustained responses to all cultural practices. Loblolly and slash pine showed similar growth responses and had a lengthened growing season (60–100 days). Slash pine growth was superior to that of loblolly. Growth responses observed during the first year continued. After 4 years, irrigation had no measurable effect on tree growth. Both pine species responded equally to F1H0 and F0H1, but slash retained a slight edge. Extra nutrients]available via fertilizer, reduced competition, or additional rooting space, increased slash-pine volume index from an average of 2.0 m³ ha⁻¹ (F0H0) to 11.90 and 13.59 m³ ha⁻¹ (F0H1 and F1H0, respectively). The F1H1 treatment produced the largest slash-pine response, diameter at breast height (D_bh) averaged 9.84 cm, height reached 5.02 m, and volume index rose to about 22.94 m³ ha⁻¹. With teh F1H1 treatment, average loblolly-pine height and volume exceeded that of the average slash pine. At age 4, the growth response due to increased nutrient supply was 13–29 times that of the best genetic response within F0H0 trees of the four slash-pine progenies. The best-growing slash-pine family (6–56) exceeded loblolly-pine growth under all four treatments and approximated the vigor shown by slash pine in the southern hemisphere.     

浙江山区茶园茶叶氟含量及影响因素

氟是人体必需的微量元素之一,它在人体生长发育和骨骼代谢中起着重要作用,摄入适量的氟有益于身体健康.但是过量摄入会导致慢性氟中毒,主要表现为氟斑牙和氟骨症等.茶树(Camellia sinensis)对土壤和环境中氟具有较强富集作用,所以茶叶中氟含量状况以及饮茶是否会摄入过量氟等问题为社会所关注(孙殿军等,2005).     

Influence of nitrogen fertilization on minerals, carbohydrates, amino acids and phenolic compounds in beech (Fagus sylvatica L.) leaves

Beginning in 1985, plots in a 120-year-old beech (Fagus sylvatica L.) stand in the province of Scania, southern Sweden were fertilized annually with ammonium nitrate. In August 1989, leaves from both fertilized and unfertilized trees were analyzed for mineral nutrients, soluble carbohydrates, amino acids and phenolic compounds. Leaf concentrations of total nitrogen were increased by N fertilization. Ammonium was not detected in the leaves, but NO(3) (-) was increased by up to 65% as a result of N fertilization. Nitrogen fertilization decreased foliar concentrations of P and Cu, leading to a nutrient imbalance relative to N. Of the free amino acids, glutamic acid and aspartic acid predominated and, together with glutamine and asparagine, were significantly increased by N fertilization. The concentrations of amides were 2-4 times higher in fertilized trees than in unfertilized trees. Soluble carbohydrates did not change in response to N fertilization, but total phenolic compounds decreased markedly. The reduced concentration of phenolics may explain the greater susceptibility to parasite attacks of trees exposed to N deposition and excess N.     

甲脒亚磺酸用于麦草Soda-AQ浆漂白的研究

对甲脒亚磷酸（ＦＡＳ）用于麦草Ｓｏｄａ－ＡＱ浆漂白的可能性进行了研究，重点考察了麦草Ｓｏｄａ－ＡＱ浆过氧化氢（Ｐ）和甲脒亚磺酸（Ａ）两段漂白中的几个过程变量（Ｈ２Ｏ２和ＦＡＳ用量、温度、时间）对漂白的影响，找出了较佳的ＰＦ漂白工艺条件。结果表明，Ｐ段Ｈ２Ｑ用量２％～３％（对绝干浆）、Ｆ段ＦＡＳ用量０．５％（对绝干浆）、温度７０℃、时间３（）ｎｄ为较佳的漂白工艺条件。研究中发现，Ｌ＊与白度呈线性正相关。ａ＊与Ｌ＊呈线性负相关，而ｂ＊与Ｌ＊之间无明确的相关性。     

Changes in freezing tolerance, plasma membrane H+-ATPase activity and fatty acid composition in Pinus resinosa needles during cold acclimation and de-acclimation

It has previously been suggested that plasma membrane ATPase (PM H+-ATPase, EC 3.6.1.3.) is a site of incipient freezing injury because activity increases following cold acclimation and there are published data indicating that activity of PM H+-ATPase is modulated by changes in lipids associated with the enzyme. To test and extend these findings in a tree species, we analyzed PM H+-ATPase activity and the fatty acid (FA) composition of glycerolipids in purified plasma membranes (PMs) prepared by the two-phase partition method from current-year needles of adult red pine (Pinus resinosa Ait.) trees. Freezing tolerance of the needles decreased from -56 degrees C in March to -9 degrees C in May, and increased from -15 degrees C in September to -148 degrees C in January. Specific activity of vanadate-sensitive PM H+-ATPase increased more than two-fold following cold acclimation, despite a concurrent increase in protein concentration. During de-acclimation, decreases in PM H+-ATPase activity and freezing tolerance were accompanied by decreases in the proportions of oleic (18:1) and linoleic (18:2) acids and increases in the proportions of palmitic (16:0) and linolenic (18:3) acids in total glycerolipids extracted from the plasma membrane fraction. This pattern of changes in PM H+-ATPase activity and the 18:1, 18:2 and 18:3 fatty acids was reversed during cold acclimation. In the PM fractions, changes in FA unsaturation, expressed as the double bond index (1 x 18:1 + 2 x 18:2 + 3 x 18:3), were closely correlated with changes in H+-ATPase specific activity (r2 = 0.995). Changes in freezing tolerance were well correlated with DBI (r2 = 0.877) and ATPase specific activity (r2 = 0.833) in the PM fraction. Total ATPase activity in microsomal fractions also closely followed changes in freezing tolerance (r2 = 0.969). We conclude that, as in herbaceous plants, simultaneous seasonal changes in PM H+-ATPase activity and fatty acid composition occur during cold acclimation and de-acclimation in an extremely winter hardy tree species under natural conditions, lending support to the hypothesis that FA-regulated PM H+-ATPase activity is involved in the cellular response underlying cold acclimation and de-acclimation.     

桉树无性系GL-UG9叶面积回归分析及其应用研究

以2年生桉树无性系GL-UG9的叶片为试验材料,利用叶面积仪测定其叶长、叶宽指标,计算出叶面积与相关指标的回归方程。结果表明:回归方程与上述指标均呈直线相关,经F检验差异达到极显著水平(p<0.01),尤其是多元回归方程y=11.753x1+4.037x2-90.805和y=-12.122x2+16.346x3-0.028x4-94.361,相关系数高达0.992 3。通过分析发现,利用回归方程测出的叶面积值与仪器实测值极为接近,该方程式为桉树无性系GL-UG9叶面积的活体测定提供了一个简单实用的测定方法。     

林茶复合经营研究与应用

本文系统地总结了林茶复合经营技术的历史沿革、3种应用类型及经营技术、科学研究成果和研究现状, 并就间作茶园树种选择原则、系统结构优化及生态学机理等研究领域提出了新的研究方向。