流苏树花形态及花香成分的时空动态变化

【目的】探究不同花香类型的流苏树的花形态和花香成分的差异,揭示流苏树花香成分时空动态变化规律,为进一步有效开发利用流苏树花及花香的遗传改良奠定基础。【方法】观察不同花香类型的流苏树不同花期花的形态特征,记录其盛花期时花序花量、花序总长、花枝长、花冠裂片长、宽和萼片长、宽。同时,采用顶空-固相微萃取(HS-SPME)和气相色谱-质谱联用(GC-MS)技术,对不同花香类型的流苏树不同花期香气成分及浓香型盛花期香气日变化进行测定分析。【结果】不同花香类型的流苏树花的形态差异主要表现在花冠裂片的颜色和形状方面,并且在盛花期时,不同花香类型的花序花量、花序总长、花枝长、花冠裂片长、宽和萼片长、宽存在显著性差异,其中浓香型的花序花量最多(49朵),花序最长,为112.67 mm,花冠裂片和萼片最大,而花枝(45.00 mm)比无香型(66.67 mm)的短,比中等香型(38.00 mm)的长,整体表现出花量大、花序长、花冠裂片大的特点。不同花香类型的流苏树在花蕾期、始花期、盛花期和末花期4个不同花期中共检测出106种花香成分,主要包括酯类、腈类、醛类、酮类、醇类、烷烃类、烯烃类、萜烯类和芳香烃类化合物。其中浓香型在4个花期中检测出的花香成分分别为0、18、45和38种,中等香型分别检测出0、7、35和19种,无香型分别检测出3、4、13和2种。在盛花期香气日变化中,浓香型流苏树共检测出86种花香成分,不同时段的花香成分差异较大,相同成分仅有17种,其中乙酸甲酯、(E)-4,8-二甲基-1,3,7-壬三烯和顺-β-法呢烯是其盛花期的主要花香成分。【结论】不同花香类型的流苏树花冠裂片颜色和形状存在明显差异,在盛花期时浓香型的花序花量、花序总长、花冠裂片长、宽和萼片长、宽的值皆为最大,而其花枝比无香型的短,比中等香型的长。浓香型花香成分种类最多,相对含量最高,其次是中等香型和无香型。花蕾期香气成分种类极少,相对含量极低,甚至为零;到始花期种类增多,相对含量增高;在盛花期花香成分种类及相对含量皆达到最大值;末花期种类减少,含量降低。浓香型盛花期整体香气含量日变化规律为先上升后下降,在14:00达到最大值。     

胡椒木释放挥发性有机物成分及变化规律

采用顶空-固相微萃取与气相色谱-质谱联用技术,对胡椒木叶片不同时期释放的挥发性有机成分及变化规律进行研究。结果表明,1 a中不同季节胡椒木释放的挥发性有机物共鉴定出37种,包括萜烯类、酯类、酸类和醇类等化合物,其中萜烯类化合物12种,酯类化合物10种,为胡椒木挥发性有机物的主要成分。胡椒木不同季节释放的挥发性有机物成分的种类和相对含量存在差异,胡椒木挥发性有机成分种类在3月份最多,24种,主要为酯类、萜烯类和酸类物质;9月份最少,8种,主要为萜烯类。1 a中,萜烯类物质的相对含量呈现先下降后上升的趋势,酯类呈现先下降后上升再下降的趋势,而烷类、酸类和醇类物质只在3月和6月出现,醛类仅在3月份出现。在6月份的日变化检测中,挥发性有机物种类呈现先减少后增多再减少的趋势,在14:00达到高峰,以萜烯类化合物为主。胡椒木不同时期释放的挥发性有机物的主要成分为肉桂酸甲酯、α-石竹烯、β-月桂烯和石竹烯等,这些有机物均具有一定的药用保健功效。因此,胡椒木是营造保健型园林景观的理想材料。     

黄金香柳叶片挥发性有机物的季节动态变化和日变化规律研究

于2012年不同季节,在深圳采集黄金香柳Melaleuca bracteata‘Revolution Gold’叶片,采用顶空-固相微萃取与气相色谱-质谱联用技术对其释放的挥发性有机物成分进行测定,分析其主要成分及其变化规律。结果表明,黄金香柳叶片一年中不同季节释放的挥发性有机物共32种,包括萜烯类、酯类、醚类、酚类、醇类和酸类等化合物,其中萜烯类18种,为挥发性有机物的主要成分;其中,6月份释放的挥发性有机物种类最多,为24种,3月份最少,为9种。同年6月采集不同时间段样叶进行挥发性有机物日变化的检测,共检测到50种,其中萜烯类23种,酸类6种、醛类4种、酯类和醇类各3种,还有少量的醚类、酚类和其他化合物;叶片释放的挥发性有机物种类在14:00和20:00最多。试验显示,黄金香柳叶片不同时期释放的挥发性有机物种类及相对含量差异明显,其主要成分肉桂酸甲酯、萜品油烯、α-水芹烯和石竹烯等均具有药用保健功效。因此,黄金香柳是营造生态型、保健型和芳香型彩色园林景观的理想树种。     

8种木犀科植物的花香成分分析与聚类分析

为了解8种木犀科(Oleaceae)植物花香成分差异,采用顶空固相微萃取法(HS–SMPE)与气相色谱-质谱联用仪(GC-MS)相结合的方法对8种木犀科植物盛花期花朵进行花香成分测定,并以此为基础对8种植物进行聚类分析。结果表明:8种植物均检测出萜烯类化合物和醇类化合物,萜烯类物质是4种丁香属植物和女贞的主要挥发物质;金叶女贞的主要挥发物是酯类和萜烯类物质,小叶女贞的主要挥发物质是酯类物质,辽东水蜡的挥发成分则是酮类物质。聚类分析将8种木犀科植物分为2类:匈牙利丁香、小叶丁香、什锦丁香、北京丁香和女贞为一类;金叶女贞、小叶女贞和辽东水蜡为一类。     

细叶石斛和翅梗石斛花朵赋香成分的GC-MS分析

[目的]本研究明确2种浓香型石斛花朵的香气成分及其含量,探明其香气组成,以期为石斛花的保健开发提供参考。[方法]采用顶空固相微萃取(HS-SPME)结合气相色谱-质谱联用(GC-MS)技术,分析了2种浓香型石斛花朵的挥发性成分。[结果]发现细叶石斛花含挥发性成分52个,翅梗石斛花含挥发性成分35个,主要成分皆为烯烃类。[结论]首次测定了翅梗石斛新鲜花朵的挥发性成分,其特征香气成分为罗勒烯、β-石竹烯和d-柠檬烯。细叶石斛花的特征香气成分为罗勒烯、β-石竹烯、芳樟醇。     

山楂和枣释放BVOCs组分生长季动态变化特征研究

【目的】探究北京地区经济林树种山楂和枣不同时期释放植物源挥发性有机物(BVOCs)组成成分的变化规律,以及两者释放有益BVOCs特征。【方法】采用动态顶空采集法收集释放的BVOCs,结合自动热脱附-气相色谱/质谱联用技术进行分析。【结果】在整个生长季从山楂叶中共检测出12类328种BVOCs,从枣叶中共检测出12类301种BVOCs,枣叶释放类别的数量与山楂叶相同,释放种类少于山楂叶,两树种均在9月释放类别最多;山楂叶和枣叶主要释放烷烃类、烯烃类和芳香烃类、酯类和醇类BVOCs;枣叶主要释放烷烃类、烯烃类、芳香烃类、酯类、醛类和醇类BVOCs,其中天然壬醛山楂叶和枣叶每月都有释放,但枣叶每月释放BVOCs的种类更加丰富;山楂是烯烃类夏季高释放量树种,枣是春季芳香烃高释放量树种;从山楂叶中共检测出烯烃类、芳香烃类、酯类、醛类、有机酸类、酮类、醇类和酰胺类8类43种有益成分,而枣叶不释放酮类,释放种类总数量比山楂叶多。【结论】两个树种释放烯烃类有益BVOCs在总有益BVOCs成分中占比最大,以释放对薄荷-1(7),3-二烯、α-蒎烯、罗汉柏烯、3-蒈烯、右旋萜二烯为主,夏季是山楂叶和枣叶释...     

卡特兰不同花期的香气成分及其变化

采用活体植株动态顶空套袋-吸附采集法与GC/MS(气相色谱/质谱联用)分析技术,研究了卡特兰‘大新1号’的香气成分及不同花期的香气变化规律。结果表明:卡特兰花蕾期的香气组成成分有42种,始花期有39种,盛花期有66种,衰落期有56种;随着花朵的开放,烯类化合物的相对含量呈先上升后下降的趋势,烷烃类和苯类化合物的相对含量总体呈上升趋势,醇类和醛酮类化合物的相对含量总体呈下降趋势。从感官分析与GC/MS的测试结果综合判断,烯类物质是影响卡特兰香气的重要化合物,3,7-二甲基-1,3,6-辛三烯、α-蒎烯、β-月桂烯、D-柠檬烯、苯甲醛、苯甲酸甲酯是卡特兰‘大新1号’的特征香气化合物。     

4种小苹果香气物质检测及主成分分析

采用超高效液相色谱法及质谱联用技术对牡丹江当地4个主栽品种果实香气组成和含量进行测定,研究不同品种间香气组成和含量的特异性差异,并进行主成分分析和聚类分析。结果表明:香气主要包括醇类、酸类、醛类、酯类、杂环类、烯烃类和烷烃类7类物质,酯类含量最多是主体香气。对其进行主成分分析发现其中24个物质是主要挥发性物质,对果实香气影响较大。通过对4种小苹果香气成分分析为当地苹果新品种选育及开发利用提供参考。     

顶空固相微萃取-气质联用分析不同发酵方式蓝莓酒的香气物质成分及特征

【目的】以低温预浸渍发酵、热浸渍发酵和带渣发酵3种不同的发酵方式所制备出的蓝莓酒为研究对象,分析3种不同发酵工艺所制备出来的蓝莓酒的香气物质成分及其含量之间的差异,为蓝莓酒发酵工艺的选择及其香气品质的分析、调控和提升提供理论依据。【方法】采用顶空-固相微萃取法(Headspace solid phase microextraction, HS-SPME)对蓝莓酒的香气成分进行萃取分离,再通过气相色谱-质谱联用技术(Gas chromatography-mass spectrometry, GC-MS)进一步分析3种发酵工艺制备的蓝莓酒的香气物质种类及其含量。【结果】低温预浸渍发酵、热浸渍发酵和带渣发酵蓝莓酒中的主要挥发性成分分别有36、39和31种,其主要为醇类、酯类、醛类、酸类、酮类、苯环类、萜烯类和烷类化合物,发酵前的蓝莓果汁中的主要挥发性成分分别有27、25和24种。与未发酵前的蓝莓果汁相比较,香气物质的种类和含量都有了显著的增加。【结论】3种不同发酵工艺所制备出的蓝莓酒的香气物质成分及含量均有一定的差异,其中以热浸渍发酵工艺所制备出的蓝莓酒的香气物质种类为最多,而以低温预浸渍发酵所制备出的蓝莓酒的香气物质含量为最高,经过对比3种发酵方式所制得的蓝莓酒的香气物质种类、含量以及特征性香气物质,低温预浸渍发酵工艺所制得的蓝莓酒品质为最佳。     

基于GC-MS的五种石斛花朵挥发性成分鉴定与差异性分析

[目的]药用石斛花朵有解郁补虚、清热消炎功效,常用于茶饮、食疗.研究5种石斛花朵的挥发性成分及其含量,探明其香气组成,以期为石斛花保健功效的开发提供参考.[方法]采用顶空固相微萃取(HS-SPME)结合气相色谱-质谱联用(GC-MS)技术,分析了肿节石斛、棒节石斛、玫瑰石斛、束花石斛、报春石斛花朵的挥发性成分.[结果]...     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Rehabilitation of diseased cacao fields in Peru through shade regulation and timing of biocontrol measures

The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased (moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to 25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol can realise their production potential.' This revised version was published online in June 2006 with corrections to the Cover Date.     

Trees and shrubs as sources of fodder in Australia

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline.     

The potential of alley cropping in improvement of cultivation systems in the high rainfall areas of Zambia I. Chitemene and Fundikila

Three trials investigating the potential of alley cropping to improve the traditional systems of cultivation, chitemene and fundikila, in the Northern Province of Zambia are described. Flemingia congesta, Tephrosia vogelii, and Sesbania sesban, were grown in association with finger millet, groundnut, cowpea, and maize in various traditional cropping sequences. The indigenous species Tephrosia vogelii and Sesbania sesban were not able to withstand repeated pruning and the long following dry season, and were replaced with Calliandra calothyrsus, and Cassia spectabilis.Over a four year period, there was no benefit by alley cropping with any of the tree species on crop yields, and yields in alley crop treatments even dropped significantly below the control treatments in the fourth year, casting doubt on the potential of alley cropping for sustainable production. There was also no consistent effect on soil chemical characteristics in any of the trials. It was suggested that this lack of beneficial response to alley cropping was due to low tree biomass production low quality of prunings, and an inappropriate cropping sequence. There was no evidence that alley cropping contributed to enhanced nutrient recycling, despite substantial localised pools of soil nutrients, particularly in the chitemene, with which recycling could potentially occur.     

Parasitism of canola aphids in France in autumn

In light of a recent increase in the aphid populations on young canola (Brassica napus) in autumn in Northwestern Europe, we carried out a survey of their parasitoid species during this season. The study was done in France from 1998 to 2001 using different sampling methods. Results highlighted the presence of two main species of Aphidiinae, Aphidius matricariae and Diaeretiella rapae (and to a lesser extent Aphidius ervi) on Myzus persicae, and of D. rapae on Brevicoryne brassicae. Nine other Aphidiinae species were found occasionally as well as some Aphelinidae parasitoids and hyperparasitoids. There was no difference in parasitoid species pattern between fields in Northern and Southern France. The principal parasitoid species found in the fields were reared in the laboratory to confirm their ability to develop on the canola aphids. Aphidius matricariae and D. rapae were reared successfully on M. persicae, but a low parasitism rate was obtained for A. ervi on this aphid. This study showed that A. matricariae and D. rapae could develop on aphids on canola and that they are present naturally in canola in autumn. However, the parasitism rate is low in autumn, so the options could be the use of these parasitoids in augmentative release biological control programs or in an IPM project on canola fields during this time of the year.     

Provenance variation in growth characters of four subtropical pine species planted in Mexico

In 1995 a species/provenance test was established in the state of Puebla, Mexico to assess and compare the growth of Pinus greggii var. australis, P. maximinoi, P. patula and P. tecunumanii, including 10, 5, 11 and 4 provenances of each species, respectively. Each provenance test lot consisted of seed from 7 to 10 individual trees collected in natural stands. Range-wide samples were included in the test for P. greggii var. australis and P. patula. Material of P. maximinoi and P. tecunumanii from Guatemala, Honduras and Nicaragua, as well as Mexico was established in the test. The test site is in a mountainous area at 1440m elevation, near 20°N latitude. At 5 years of age significant differences were seen at both the species and provenance levels in survival, total height, diameter and volume. The overall test survival was 93%. Variance among species was three time greater than among provenances, comprising 25–33% of the total variation. P. maximinoi had the greatest height, diameter and volume (62dm³) followed by P. tecunumanii (53dm³). P. greggii var. australis had an average volume of 43dm³ and P. patula produced 30dm³. Although P. maximinoi had the lowest survival rate, the San Jeronimo provenance was the most productive of all 30 provenances tested; 98% survival and 73dm³ volume. This was equivalent to 2.8cm annual diameter increment and 2m in height growth per year. Significant growth differences among provenances within species indicate that potential gain exists using provenance selection.     

Inhibition of Trypanosoma cruzi by plant extracts used in Chinese medicine

In this work, we assessed the effect of extracts obtained from 17 plants used in traditional Chinese medicine. These extracts were tested in vitro with the epimastigote form of Trypanosoma cruzi, clone Bra C(15) C(2), at 27 degrees C in F-29 medium at a concentration of 100 microg/ml in axenic cultures. Allopurinol was used as reference drug. Seven plant extracts showed inhibitory activities lower than 25%. Pueraria lobata, Mahonia beaei, Dictamus dasycarpus, Kochia scoparia, Sophora flavescens and Ligustrum lucidum showed effects with inhibition values between 25% and 60%, whereas Lithospermum erythrorhizon, Saussurea lappa, Melia toosendan and Cinnamomum cassia showed the greatest inhibitory activity of 100%. The IC(50) of these extracts were: 0.4, 2.4, 1.8 and 3.9 microg/ml, respectively. The MTT assay was made and did not show cytotoxic activity. These results allowed us to suggest that L. erythrorhizon, S. lappa, M. toosendan and C. cassia could be a source of new compounds against T. cruzi.     

Effects of thinning on growth of six tree species in north-temperate forests of Lithuania

This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over 100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen, while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands, e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce.     

Impact of tree coppicing on tree-crop competition in parkland and alley farming systems in semiarid Burkina Faso

The aim of this study was to evaluate the effects of tree coppicing on tree-crop competition in farmed parkland and in alley farming, both in semiarid Burkina Faso.Azadirachta indica A. Juss (neem) was studied in the parklands, while neem,Albizia lebbeck (L.) Benth. (albizia) andLeucaena leucocephala (Lam.) de Wit (leucaena) were investigated in the alley farming system. The crop was sorghum (Sorghum bicolor (L.) Moench) in both cases.Under non-coppiced neem trees in the parkland, the sorghum yield at 0–3 m distance from the tree (under the tree canopy) was 82% of open field yields at 6–9 m distance, but the difference was not significant (p=0.07). Close to trees (0–3 m distance) which had been coppiced before planting, the sorghum yield was 148% of open field yields. In alley farming, early coppicing was superior; sorghum yields were highest close to trees coppiced early and lowest close to trees coppiced late.

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Résumé La présente étude se propose d'évaluer les effets de la taille sur la concurrence entre arbres et cultures dans les parcs arborés et dans les cultures en couloir, en climat semiaride (Burkina Faso). Les espèces étudiées ont été:Azadirachta indica A. Juss (neem) dans les parcs et neem,Albizia lebbeck (L.) Benth. (albizia) ainsi queLeucaena leucocephala (Lam.) de Wit (leucaena) dans les cultures en couloir. Dans les deux cas la plante cultivée concerné a été le sorgho blanc (Sorghum bicolor (L.) Moench).Sous les neems non taillés des parcs, le rendement du sorgho cultivé de 0 à 3 m de l'arbre (sous le bouppier de l'arbre) a atteint 82% du rendement obtenu en plein champ, soit à une distance de 6 à 9 m de l'arbre (différence non significative,p=0.07). Une taille effectuée en début de campagne a entraîné un accroissement du rendement de 148% pour les cultures situées de 0 à 3 m de l'arbre, par rapport aux rendements en plein champ.Dans les cultures en couloir, on a constaté qu'une taille precoce est préférable, c'est à dire que les rendements de sorgho ont été supérieurs dans les lignes proches des arbres taillés tôt que dans celles proches des arbres taillés tard.

     

Initial growth of pioneer timber tree species in a Taungya system in the humid lowlands of Costa Rica

The temporary association of annual crops in juvenile tree plantations (Taungya system) can reduce or offset the initial costs of reforestation and hence provide incentives for tree planting on private farms. A replicated systematic spacing design, derived from a Nelder-fan design, was used to study the effects of tree-crop distance on growth and development of the timber species salmwood (Cordia alliodora) or eucalyptus (Eucalyptus deglupta), associated with maize (Zea mays) or cassava (Manihot esculenta), during the first year after transplanting the trees on two sites on alluvial soils in the humid lowlands of Costa Rica. Association with maize did not affect mean tree growth. However, mean eucalyptus and salmwood heights of 7–8 m and 3–4 m, respectively, after one year in pure plantation or associated with maize, were only 4.7 m and 1.4 m, respectively, when associated with cassava. Wider tree – crop spacings were more important for initial salmwood growth than for eucalyptus. It was concluded that the shoot growth characteristics (continuous or episodical growth) of the timber species is a very important consideration when selecting associated agricultural crop species and tree-crop distances.