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1.
A qualitative and quantitative analysis of rutin from leaves, fruits and flowers of Capparis spinosa growing wild in Khuzestan was achieved. After soxhelet extraction of fats in diethyl ether, rutin was extracted by maceration using 50% EtOH. The ethanol extracts of these parts were separated by preparative TLC on silica gel precoated plate with a mixture of butanol: acetic acid (4:1, by volume) as the developing solvent. The spots were visualized under ultraviolet light (254 nm). Rutin was qualified by comparison of its R(f) value with that of standard. UV/Vis spectrum of separated rutin was also compared with those of standards and showed characteristic wavelengths at 260 and 360 nm. Purified rutin was quantified by UV/Vis spectrophotometric determination at 360 nm. The calibration curve was linear in the range of 0.156-2.5 microg mL(-1) with detection limit of 0.0731 microg mL(-1). The purity of extracted rutin from leave, flower and fruit determined by high performance liquid chromatography were 90.41, 87.25 and 64.56%, respectively. The amounts of rutin in leaves, fruits and flowers were 61.09, 6.03 and 43.72 mg per 100 g of dried powder, respectively. By analyzing the spiked samples of leave, flower and fruit the recovery of the UV/Vis method was in the range of 102-107.6%. 相似文献
2.
木奶果醇提物的抗氧化活性及其对Aβ25-35致PC12细胞损伤的神经保护作用 总被引：1，自引：0，他引：1
为了探明木奶果不同部位的总酚含量和抗氧化活性及其对Aβ25-35致PC12细胞损伤的神经保护作用的差异,以期为木奶果高价值产品开发提供理论依据。以木奶果果皮、果肉、果核3个部位醇提物为研究对象,采用Folin-Ciocalteu法、DPPH、ABTS、羟基自由基清除能力测定体外抗氧化活性,并采用Aβ25-35诱导PC12细胞成阿尔兹海默病细胞模型测定醇提物对不同浓度Aβ25-35所致PC12细胞损伤的神经保护作用。结果显示:木奶果果皮、果肉、果核3个部位的总酚含量分别为(101.03±5.99)、(16.03±1.13)、(51.27±4.02)mg GAE/g干物质;抗氧化活性与样品浓度存在剂量关系,其中果皮的抗氧化活性最强,果核次之,果肉最差;果皮醇提物对Aβ25-35所致PC12细胞损伤的神经保护作用最佳,当木奶果果皮醇提物浓度为1 mg/m L时,能将Aβ25-35诱导的PC12细胞致死率从(41.6±1.36)%降为(11.95±1.98)%;PC12细胞的凋亡率从(84.69±5.78)%降至(25.26±3.18)%。可见,木奶果醇提物对Aβ25-35所致PC12细胞氧化损伤具有很好的保护作用。 相似文献
3.
为了探究千层金叶片醇提物的抗氧化活性,本文研究了千层金叶片醇提物及其不同极性部位的抗氧化活性和总多酚含量。研究结果表明：千层金叶片醇提物正丁醇相的总多酚含量最高,为(453.75±0.75) mg/g;75%甲醇粗提物及其正丁醇相对ABTS +自由基的清除能力较抗坏血酸（VC）强;各组分还原力强弱顺序为VC>正丁醇相>75%甲醇粗提物>水相>乙酸乙酯相>BHT>石油醚相;正丁醇相和乙酸乙酯相对DPPH自由基的清除能力较醇提物和水相强,石油醚相最弱;千层金叶片醇提物及其不同极性部位清除ABTS +自由基清除能力、DPPH自由基清除能力及还原力均与其总多酚含量呈正相关。除石油醚相外,千层金叶片醇提物及其不同极性部位均有较强的抗氧化活性,可作为一种良好天然抗氧化剂的物质来源。 相似文献
4.
确定辣木叶中γ-氨基丁酸的最佳提取条件,并评价其体外抗氧化活性。通过单因素试验和正交试验优化辣木叶γ-氨基丁酸提取工艺参数,研究提取温度、料液比和提取时间等因素对辣木叶γ-氨基丁酸提取率的影响。结果表明:最佳提取条件为提取温度为60℃、料液比为1∶15、提取时间为30 min,在此条件下,辣木叶γ-氨基丁酸含量为(3.40±0.09)mg/g,γ-氨基丁酸粗提物对DPPH自由基、羟自由基以及ABTS自由基清除能力较强,其EC50分别为0.149 0 mg/m L、0.092 5 mg/m L和0.039 8 mg/m L,呈剂量依赖性。 相似文献
5.
为研究铁观音提取物和荆芥提取物联用在抗氧化方面的协同作用,采用水浸提法分别萃取铁观音和荆芥得其抗氧化活性成分。以芦丁为标准品检测两种提取物类黄酮含量,其中铁观音提取物为15.13 mg/g,荆芥提取物为0.87 mg/g;以没食子酸为标准品检测两种提取物的总酚含量,其中铁观音水提物为50.87μg/mg,荆芥水提物为47.40μg/mg。用2,2-二苯基-1-苦基肼(DPPH)和2,2'-二氮-双(3-乙基苯并噻唑-6-磺酸)(ABTS)法评估两种提取物联合应用时的抗氧化活性,结果表明,在较低浓度时,铁观音与荆芥提取物联用具有协同增强抗氧化作用。 相似文献
6.
嘉宝果嫩叶提取物不同极性部位抗氧化及抑制α-葡萄糖苷酶活性研究 总被引：1，自引：0，他引：1
从植物中寻找天然的抗氧化剂和α-葡萄糖苷酶抑制剂对糖尿病患者具有重要的意义。采用比色法对嘉宝果嫩叶醇提物不同极性部位进行总多酚和总黄酮含量、抗氧化活性及α-葡萄糖苷酶活性抑制活性研究,以期为嘉宝果嫩叶有效提取部位在食品、化工及医学领域的应用提供一定的参考依据。结果表明,乙酸乙酯相的总多酚含量（33.92 mg/g及总黄酮含量（13.35 mg/g）最高,其次为正丁醇相（总多酚31.11 mg/g;总黄酮12.93 mg/g）及水相（总多酚17.04 mg/g;总黄酮11.18 mg/g）;石油醚相及二氯甲烷相均未检测到总多酚及总黄酮。乙酸乙酯相与正丁醇相对DPPH及ABTS +自由基的清除能力相当,明显高于其他极性部位。对酵母源和小鼠小肠源α-葡萄糖苷酶活性抑制活性大小依次分别为乙酸乙酯相>正丁醇相>水相>石油醚相>二氯甲烷相和乙酸乙酯相>正丁醇相>水相>二氯甲烷相>石油醚相。以上结果表明嘉宝果嫩叶乙酸乙酯相与正丁醇相总多酚及总黄酮含量较高,抗氧化活性及对α-葡萄糖苷酶活性的抑制作用较强,是挖掘抗氧化及抑制α-葡萄糖苷酶活性物质的主要极性部位。 相似文献
7.
植物抗氧化研究对寻找高效率、低毒性天然抗氧化剂具有重要的指导意义。以在海南分布较广的红树林植物海莲进行抗氧化活性研究,以期对海莲开发利用的可能性提供理论依据。采用清除DPPH自由基和清除ABTS自由基对海莲不同部位———根、茎、叶、花的乙酸乙酯提取物进行抗氧化能力评价,采用比色法和福林酚法测定总黄酮和总酚含量。结果显示,海莲茎的提取物在4个部位中抗氧化活性最好,清除二者的IC50分别为(0.234±0.053)mg/m L和(0.196±0.080)mg/m L,海莲中酚类物质含量较大,4个部位中茎的总酚含量最多,含量为13.2 mg。说明海莲各部位均显示出了较好的抗氧化能力,具有较好的开发潜力。 相似文献
8.
I. Erdogan Orhan E. GunerN. Ozturk F.S. SenolS. Aslan Erdem M. KartalB. Sener 《Industrial Crops and Products》2012,37(1):213-218
In the present study, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase inhibitory and antioxidant activities of the fruit and leaf extracts of Melia azedarach L. (Meliaceae) of Turkish origin were evaluated. Enzyme inhibitory activity of the extracts was tested in vitro using ELISA microplate reader. Antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelation, and ferric-reducing antioxidant power (FRAP) assays. Phenolic composition of the extracts was elucidated by high performance liquid chromatography (HPLC) and fatty acid compositions of the fatty oils of the fruits and leaves were elucidated by gas chromatography-mass spectrometry (GC-MS). The ethyl acetate extract from the leaves showed the highest inhibition against AChE (33.63 ± 1.40%) and BChE (92.89 ± 3.05%). The methanol extract from the leaves exerted the best antioxidant activity in DPPH radical scavenging and FRAP assays, while the ethyl acetate extracts of the fruits and leaves had the most notable effect in metal-chelation assay. 相似文献
9.
Motlhanka DM 《Pakistan journal of biological sciences: PJBS》2008,11(5):805-808
Water and methanol extracts from roots of Ozoroa paniculosa (Anarcardiaceae); seeds of Colophospermum mopane (Caesalpiniaceae) and Cucumis metuliferus (Cucurbitaceae) ripe fruits were assessed for in vitro antioxidant activity. Free radical scavenging activity was measured spectrophotometrically as maximum fading power of DPPH at 525 nm. Water and methanol extracts of Ozoroa paniculosa exhibited higher scavenging potency than extracts of either Colophospermum mopane or Cucumis metuliferus at all tested concentrations. None of the extracts from Cucumis metuliferus exhibited any recognizable free radical scavenging activity. Above 50 microg mL(-1) both water and methanol extracts of Ozoroa paniculosa exhibited 91% scavenging activity similar to the control compounds L-ascorbic acid (91%) and (-) epicatechin (92%). Between 50-100 microg mL(-1), water and methanol extracts of Colophospermum mopane exhibited scavenging potency of < or = 70%. However, above 100 microg mL(-1), both water and methanolic extracts of C. mopane exhibited scavenging activity > 70%. Chloroform extracts of all the tested plants showed poor scavenging activity (< 30%). The order of scavenging potency for the tested samples was as follows: L-ascorbic acid > or = epicatechin > O. paniculosa (methanolic extract) > O. paniculosa (water extract) > O. paniculosa (ethylacetate extract) > C. mopane (methanolic extract) > C. mopane (water extract) > all extracts of C. metuliferus. These findings lend credence to the use of these plants as anti-inflammatory and antioxidant agents in folk medicine. 相似文献
10.
Riccardo Trentin Luísa Custdio Maria Joo Rodrigues Emanuela Moschin Katia Sciuto Jos Paulo da Silva Isabella Moro 《Marine drugs》2022,20(3)
This work studied the potential biotechnological applications of a naviculoid diatom (IMA053) and a green microalga (Tetraselmis marina IMA043) isolated from the North Adriatic Sea. Water, methanol, and dichloromethane (DCM) extracts were prepared from microalgae biomass and evaluated for total phenolic content (TPC) and in vitro antioxidant properties. Biomass was profiled for fatty acid methyl esters (FAME) composition. The DCM extracts had the highest levels of total phenolics, with values of 40.58 and 86.14 mg GAE/g dry weight (DW in IMA053 and IMA043, respectively). The DCM extracts had a higher radical scavenging activity (RSA) than the water and methanol ones, especially those from IMA043, with RSAs of 99.65% toward 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS) at 10 mg/mL, and of 103.43% against 2,2-diphenyl-1-picrylhydrazyl (DPPH) at 5 mg/mL. The DCM extract of IMA053 displayed relevant copper chelating properties (67.48% at 10 mg/mL), while the highest iron chelating activity was observed in the water extract of the same species (92.05% at 10 mg/mL). Both strains presented a high proportion of saturated (SFA) and monounsaturated (MUFA) fatty acids. The results suggested that these microalgae could be further explored as sources of natural antioxidants for the pharmaceutical and food industry and as feedstock for biofuel production. 相似文献
11.
主栽品种龙眼生物学性状及营养累积特点 总被引：2，自引：0，他引：2
在华南龙眼主产区挖取16~17 a成熟期中高产石硖、储良、福眼和松风本龙眼（Dimocarpus longan Lour.）各1株,调查树体生物学性状,探讨养分元素在树体的累积和分配。结果显示,4株龙眼地上部树体生物量平均为264.3 kg（鲜重）,果实、叶片和树干分别占地上部生物量的28.4%、12.3%和59.3%。在果实成熟期,叶片、树干、根系和果皮均以Ca含量最高,果肉以K含量最高,果核N含量最高。为生产50 kg果实,龙眼地上部需吸收N 668.6 g、P 102.0 g、K 461.6 g、Ca 1310.4 g、Mg 80.7 g、S 43.3 g、Si 63.8 g、Fe 20.1 g、Mn 5.8 g、Cu 349.9 mg、Zn 1245.9 mg、B 849.5 mg和Mo 8.7 mg。Ca是龙眼最重要的营养元素。收获50 kg龙眼果实,带走养分量为N 167.8 g、P 23.1 g、K 156.4 g、Ca 57.0 g、Mg 12.6 g、S 8.4 g、Si 0.7 g、Fe 0.7 g、Mn 0.4 g、Cu 110.5 mg、Zn 155.6 mg、B 125.3 mg和Mo 1.6 mg。为维持立地土壤养分肥力及龙眼植株正常生长,果实带走养分量应为翌年施肥量的下限。对生产中因营养问题引起的龙眼叶片缺素和果实生长异常现象进行讨论后,建议今后加强龙眼Ca、Mg、Si和B营养的研究。 相似文献
12.
Santos-Cervantes ME Ibarra-Zazueta ME Loarca-Piña G Paredes-López O Delgado-Vargas F 《Plant foods for human nutrition (Dordrecht, Netherlands)》2007,62(2):71-77
We report for the first time the antioxidant and antimutagenic activities of fractions from Randia echinocarpa fruit, which is a Rubiaceae plant native to Sinaloa, Mexico. This fruit has been traditionally used in the prevention or treatment of cancer, among other
diseases. The pulp of the fruit was sequentially extracted with solvents of different polarity (i.e. hexane, chloroform, methanol
and water). A high extraction yield was obtained with methanol (72.17% d.w.). The aqueous extract showed the highest content
of phenolics (2.27 mg/g as ferulic acid equivalents) and the highest antioxidant activity based on the β-carotene bleaching
method (486.15). The commercial antioxidant BHT was used as control (835.05). Antimutagenic activity of the aqueous extract
(0–500 μg/tube) was evaluated using the Salmonella microsuspension assay (YG1024 strain) and 1-NP as the mutagen (50 and 100 ng/tube). The aqueous extract was neither toxic
nor mutagenic and the percentage of inhibition on 1-NP mutagenicity was 32 and 53% at doses of 50 and 100 ng/tube, respectively.
The results of the double incubation assay suggest that the extract inhibited the mutagenicity of 1-NP by a combination of
desmutagenic and bioantimutagenic effects. 相似文献
13.
Jastrzebski Z Tashma Z Katrich E Gorinstein S 《Plant foods for human nutrition (Dordrecht, Netherlands)》2007,62(4):145-150
Prolipid a known mixture of herbs is used as a plasma lipid lowering medicine. No side effects were registered. However, the
bioactive substances of Prolipid were not investigated. Therefore in this investigation Prolipids bioactive compounds and
antioxidant activity were studied. The contents of polyphenols and flavonoids were 19.87 ± 2.09 and 3.09 ± 0.31 mg gallic
acid equivalent GAE/g DW and 2.09 ± 0.24 and 0.57 ± 0.05 mg catechin equivalent CE/g DW in water and methanol fractions, respectively.
Anthocyanins (0.02 ± 0.001 mg/g DW) and flavanols (7.58 ± 0.81 μg CE/g DW) were found only in water fraction. The antioxidant
activity of Prolipid, as determined by four different antioxidant assays [ferric-reducing/antioxidant power (FRAP); cupric
reducing antioxidant capacity (CUPRAC); trolox equivalent antioxidant capacity (TEAC); 1, 1-diphenyl-2-picrylhydrazyl radical
(DPPH)], was higher in water than in methanol fraction. The correlation coefficients between polyphenols, flavonoids and antioxidant
activities of Prolipid water extracts with TEAC were 0.97 and 0.90, respectively. It can be concluded that the content of
polyphenol compounds in Prolipid is very high and they are the main contributors to Prolipids overall antioxidant activity.
Prolipid is widely used in human treatment without known side effects on patients and is comparable to other medicinal plants,
and as a strong antioxidant mixture could be used as a supplement to known atherosclerosis preventing diets. 相似文献
14.
为比较不同品种荔枝果皮酚类物质含量、组成及其抗氧化活性差异,用80%甲醇分别提取6个品种荔枝果皮中的酚类物质,测定其总酚和总黄酮含量。采用铁离子还原能力（FRAP）和自由基离子清除能力（ABTS）等方法评价其抗氧化活性。通过高效液相色谱（HPLC）鉴定不同的单体酚并分析其在不同品种荔枝果皮之间的差异。结果表明,不同品种荔枝果皮的酚类物质含量为28.69~68.48 mg/g,不同品种荔枝果皮的酚类物质含量和抗氧化能力存在显著的差异（P<0.05）。酚类物质的含量、FRAP和ABTS抗氧化活性能力均以‘荔枝王’为最高,分别为68.48 mg/g、546.31 μmol/g和511.25 μmol/g。液相色谱结果鉴定出‘糯米糍’中的8种单体酚,而含量相对较高的是A型原花青素三聚体和原花青素A2。研究结果可为荔枝加工废弃物荔枝果皮的开发利用提供理论依据。 相似文献
15.
为优化工业大麻中CBD提取工艺,建立CBD高效液相分析方法,评估CBD体外酶抑制活性和抗氧化活性,拟通过设计单因素实验,以溶剂种类、超声时间、料液比、提取次数为影响因素,CBD含量为评价指标优化提取工艺,并通过检测CBD对黄嘌呤氧化酶、多酚氧化酶的抑制率及ABTS自由基的清除率监测其体外酶抑制活性。结果表明:甲醇为提取溶剂、提取2次、超声10 min、料液比1:20 g/mL为最佳提取条件。生物活性实验表明CBD能明显抑制酶活,其对XOD、PPO、ABTS的C50分别为1.18μg/mL(40s)、1.03μg/mL (60s)、4.99μg/mL和1.68μg/mL。该工艺操作简单、稳定可靠、成本较低,为工业大麻花叶中CBD的提取及定性定量提供一种新的技术方法,且该方法提取的CBD酶抑制活性和抗氧化活性好,具有重要的药用价值。 相似文献
16.
Antioxidant Properties and Preliminary Evaluation of Phytochemical Composition of Different Anatomical Parts of Amaranth 总被引：1，自引：0，他引：1
Paulius Kraujalis Petras R. Venskutonis Vaida Kraujalienė Audrius Pukalskas 《Plant foods for human nutrition (Dordrecht, Netherlands)》2013,68(3):322-328
Antioxidant properties of amaranth extracts isolated sequentially by acetone and methanol/water from defatted plant leaves, flowers, stems and seeds were assessed by ABTS+?, DPPH?, ORAC and total phenols content (TPC) assays. In addition, antioxidant properties of solid plant material were evaluated by the direct QUENCHER method using the same assays. Leaves and flowers of amaranth as well as their extracts possessed the highest antioxidant activities. Radical scavenging capacity in ABTS+? assay for leaves, flowers, stems and seeds evaluated by QUENCHER method were 144.24?±?2.41, 112.33?±?7.45, 19.05?±?1.13 and 21.82?±?1.06 μmol trolox equivalents in 1 g of dry weight, respectively. On-line HPLC-DPPH? assay was used to determine the activity of separated compounds and it was observed that rutin was the main radical scavenger in amaranth extracts. Preliminary screening of extract composition was performed by UPLC/ESI-QTOF-MS and rutin, nicotiflorin, isoquercitrin, 4-hydroxybenzoic and p-coumaric acids were identified by measuring their accurate mass and retention time. 相似文献
17.
假臭草浸提液对玉米根系活力的影响 总被引：1，自引：0，他引：1
对不同假臭草浸提液处理的玉米幼苗根系活力进行测定,并通过生物活性作用响应指数RI(response index)研究假臭草浸提液的化感作用强度。结果表明,在假臭草浸提液浓度分别为0.0125g(FW)/mL(A1)、0.025g(FW)/mL(A2)、0.05g(FW)/mL(A3)时,对玉米根系影响的RI平均值分别为-0.1675、-0.3033、-0.4706,假臭草浸提液浓度越大,RI值随之越大;假臭草新鲜茎叶(B1)、新鲜根系(B2)、烘干茎叶(B3)及烘干根系(B4)组织浸提液对玉米根系影响RI平均值分别为-0.5251、-0.2651、-0.2379、-0.2272;不同浓度及不同组织浸提液交互作用间,在0.05g(FW)/mL(A3)浓度下,假臭草新鲜茎叶组织对玉米根系影响的RI平均绝对值最大(RI=-0.8949),在0.0125g(FW)/mL(A1)浓度下,假臭草新鲜茎叶组织对玉米根系影响的RI平均绝对值最小(RI=-0.1252)。假臭草浸提液具有一定的化感作用,浓度越高,其化感作用越强,茎叶组织浸提液的化感作用比根系浸提液的强,新鲜假臭草组织的化感作用比烘干组织的强。 相似文献
18.
Total Phenolics Level,Antioxidant Activities and Cytotoxicity of Young Sprouts of Some Traditional Korean Salad Plants 总被引：2，自引：2，他引：0
Sang-Uk Chon Buk-Gu Heo Yong-Seo Park Dong-Kwan Kim Shela Gorinstein 《Plant foods for human nutrition (Dordrecht, Netherlands)》2009,64(1):25-31
The aim of this investigation was to study the antioxidant and anticancer activities of young sprouts of some traditional
Korean salad plants. Total phenolics, antioxidant and anticancer activities of the methanol extracts from young sprouts of
11 salad plants were determined. The highest amount of phenolics was found in methanol extracts of Euonymus alatus (235.7 mg kg−1), followed by Hypericum ascyron (197.1 mg kg−1), Zanthoxylum piperitum (194.1 mg kg−1) and Zanthoxylum schinifolium (142.5 mg kg−1). Methanol extracts of E. alatus, H. ascyron, and Z. piperitum at 63 mg kg−1 exhibited the highest dose-depend DPPH radical scavenging activity by 91.2, 91.2 and 83.9%, respectively. According to the
MTT results, the methanol extracts from Stellaria aquatica, Eleutherococcus sessilifolrus and Z. schinifolium showed the highest anticancer activities against Calu-6 (IC50 < 25.0 μgml−1) and from S. aquatica—the highest anticancer activities against SNU-601 (153.3 μgml−1), following by E. sessilifolrus (196.7 μg ml−1) and Amaranthus mangostanus (303.1 μgml−1). Total phenolics were highly correlated with the DPPH, suggesting that they contribute to the antioxidant properties of
the studied plants. In conclusion: young sprouts of Korean salad possess antioxidant and anticancer properties and could be
used as a supplement to proper drugs. 相似文献
19.
Thymus vulgaris L., known as common thyme, is a perennial subshrub native to the Mediterranean region. The use of the extracts and herb of thyme plants as antibacterial, antioxidant, natural food preservative and in cosmetic industry has increased the economic importance of this medicinal crop worldwide. Agricultural practices have an influence on growth and yield of thyme plants. Therefore, an experiment was undertaken to determine the effects of three intra-row spacing (15, 30 and 45 cm) and four harvesting times (vegetative, beginning of blooming, full blooming and fruit set) on plant growth and herbage biomass of thyme in 2007 in the research farm of Shoubak University College in the southern part of Jordan. The experiment was a split plot in randomized complete block design with four replicates. Apart from the experiment in 2007, measurements taken on the 15th of November in 2008 were treated as an independent experiment irrespective of harvesting stage. The effects of spacing were not significant for all the parameters measured in 2007. Intra-row spacing in 2008 had significant effects (P < 0.05) on plant height, canopy diameter, herbage fresh and dry weight and number of leaves on long shoots. Its effect on dry weight of shoots, fresh and dry weight of long shoots, number of long shoots, root depth, leaf area and specific leaf area was very significant (P < 0.01). Results of this study indicated that thyme plants grown using 15 cm planting space and harvested at the fruit set stage in 2007 had the highest fresh and dry weight of shoots. The highest dry weight of shoots, herbage fresh and dry weight was also obtained in 2008 in 15 cm spacing. Closer spacing resulted in significantly taller plants that exhibited higher shoot:root ratio and, therefore, plants grown using 15 cm intra-row spacing had a better use of light and accumulated more biomass compared to plants in wider spacing. The differentiation between long shoots and short shoots throughout plant development in 2007 suggests a specialization in carbon gain along different times in the growing season. Swings observed for shoot:root ratio, leaf area and specific leaf area were related to thyme growth. The decrease in specific leaf area between vegetative and full bloom stage indicated that leaves became thicker as part of an adaptive mechanism to the surrounding environment. Information obtained from growth parameters, leaf area and specific leaf area in particular, could be related to essential oil production in leaves of thyme plants. 相似文献
20.
Kolahi M Peivastegan B Hadizade I Abdali A 《Pakistan journal of biological sciences: PJBS》2008,11(14):1825-1829
Phytotoxicity of barley extracts (Hordeum vulgare L.) on wild oat (Avena ludoviciana Durieu) was investigated. Water extracts five varieties of barley were bioassayed on germination and seedling growth of wild-oat to test the heterotoxicity of barley on wild-oat, study the dynamics of allelopathic potential over four growth stages and identify the most allelopathic plant part of barley in each stage. Whole barley plants were extracted at growth stage 4 (stems not developed enough), whilst for the following growth stages roots, stems, panicles and leaves were extracted separately. Seedling growth bioassays demonstrated that the wild-oat responded differently to the allelopathic potential of barley. For wild-oat radical growth and coleoptile growth were more depressed than germination, though. The allelopathic potential of barley plant parts was not stable over its life cycle for wild-oat. Leaves and stems were the most phytotoxic barley plant parts for wild-oat in the all stages. Among the varieties Eizeh appeared as the best one showing toxicity to seed germination of wild oat at its stage 4 and 8. Results suggested that the response by wild-oat varied depending on the source of allelochemicals (plant part) and the growth stage of the barley plant and kind of variety. The results leaded to conclude that Eizeh variety of barley was good to grow as it has good check on seed germination of wild oat plants as well as it also retarded the growth of root and shoot length of oat. 相似文献