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1.
植物化感作用在草地生态系统中的研究进展   总被引:2,自引:1,他引:1  
植物的化感作用(allelopathy)是植物化学生态学研究的热点之一。在生态系统中化感植物通过淋溶、挥发、残体分解和根系分泌等过程,释放出化学物质,引起植物种间或种内的相互作用,产生有害或有利的影响。化感作用影响着群落的植物组成及分布格局、群落的演替、种子的保存和萌发以及氮循环等。主要对草地植物的化感物质种类、化感物质作用特点、释放途径、影响化感物质产生的因素以及化感物质提取方法进行了归纳和总结。同时,提出了草地植物化感研究存在的科学问题和应用前景。  相似文献   
2.
西芹鲜根及根际区物化感物质成分鉴定   总被引:1,自引:0,他引:1  
陈磊  云兴福 《华北农学报》2012,27(2):157-164
为探讨西芹鲜根及根际区物化感物质成分,利用柱层析法及GC-MS对西芹鲜根及根际区物不同浸提液二次层析后化感效应最佳流分进行分离鉴定。结果表明,西芹鲜根与根际区物乙醇浸提液二次层析后化感效应最佳流分的主要化感成分均为4-二甲氨基-2-甲基-1-苯基-丁-2-醇、8-十八烯酸甲酯、棕榈酸甲酯、十八烷二烯酸甲酯;西芹鲜根与根际区物丙酮浸提液二次层析后化感效应最佳流分的主要化感成分为2-丙烯酸十五烷基酯;西芹鲜根与根际区物水浸提液二次层析后化感效应最佳流分的主要化感成分为十六烷基二甲基叔胺、14-甲基十五烷酸甲酯、六甲基环三硅氧烷、(E)-9-十八烯酸甲酯、蓖麻油酸甲酯、16-甲基十七烷酸甲酯。  相似文献   
3.
地黄根系分泌物生物活性研究及化感物质的鉴定   总被引:3,自引:0,他引:3  
采用砂粒为培养地黄苗的基质,利用XAD-4柱循环收集地黄根系分泌物,通过对地黄、莴苣、芝麻、萝卜的生物测定,将有影响的组分进行GC-MS物质鉴定。研究结果显示:根系分泌物的酸性组分和中碱性组分对作物胚根和胚芽伸长都有抑制作用,随添加量的增加抑制加强,其中对萝卜胚根的影响表现为低促高抑。分别将两种组分进行GC-MS物质鉴定,发现在两种组分中都含有长链脂肪酸和阿魏酸等常见的化感物质。  相似文献   
4.
利用开放式空气CO2浓度升高(Free Air Carbon-dioxide Enrichment, FACE)平台, 研究了低氮(LN)和常氮(NN)水平下, 大气CO2浓度升高对冬小麦叶片酚酸类物质代谢的影响.结果表明, CO2浓度升高对小麦叶片水杨酸、对羟基苯甲酸、肉桂酸、阿魏酸和香草酸含量的影响随供氮水平的不同而有所差异.低氮下小麦通过提高叶片苯丙氨酸解氨酶(PAL)活性(30.1%)而使其含量均显著增加, 增幅分别达33.7%、119.6%、26.7%、39.9%和28.6%; 而常氮下PAL活性和酚酸类含量变化均未达显著水平.可见, 大气CO2浓度升高对冬小麦酚酸类物质代谢的影响受氮水平的调控, 在未来CO2浓度升高条件下, 选择适宜的施肥水平将显得更为重要.此外, 总酚含量与水杨酸、对羟基苯甲酸、肉桂酸、阿魏酸和香草酸等含量变化趋势基本一致, 且总酚含量变化的79.6%~151.4%是由这几种酚酸含量变化引起的, 说明CO2浓度升高使水杨酸、对羟基苯甲酸、肉桂酸、阿魏酸和香草酸等含量增加是总酚含量增加的直接原因.低氮条件下大气CO2浓度升高将通过改变酚酸类物质代谢而间接影响小麦与伴生杂草的关系.  相似文献   
5.
[目的]研究大蒜浸提液对菜豆种=产萌发的化感作用强度。[方法]以乙醇为提取剂对大蒜进行提取,用大蒜浸提液处理4个菜豆品种(安蔬高产架豆王、赤裕五号、赤裕三号、抗病泰国新架豆王),测定不同处理的发芽势、发芽率、发芽指数、活力指数、幼苗长度、电导率和POD活性。[结果]大蒜浸提液对4个品种发芽率的抑制率都在20%以下,种子活力指数的抑制率均达80%以上,对幼苗长度的抑制率均达70%以上,对抗病泰国新架豆王发芽势和发芽指数的抑制率最大,分剐为71%和65%。经大蒜浸提液处理后,幼苗电导率和POD活性显著提高。安蔬高产架豆王和赤裕五号的POD活性分别提高了69%、68%。[结论]大蒜化感物质对菜豆种子萌发有较强地抑制作用。  相似文献   
6.
Comparative evaluation of sunflower aqueous extracts and commercially available synthetic herbicides was carried out in field trials. Crude aqueous extract was tested in 80 and 100% concentrations in plots where wheat was grown with Rumex dentatus in a 1:1 mix. In comparison with the synthetic herbicides (Buctril-Super® and Chwastox®) the aqueous extract failed to kill 100% of selected weeds, but the highest tested extract concentration completely overcame weed crop competition by reducing the weed biomass and increasing wheat yield significantly. The trial confirmed the herbicidal potential of sunflower allelochemicals against broad leaf weeds.  相似文献   
7.
The aim of this study was to evaluate resistance to Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) by antixenosis on 57 Lycopersicon esculentum Mill. accessions from the Horticultural Germplasm Bank (HGB) of Universidade Federal de Viçosa and by the three commercial cultivars (Santa Clara, Moneymaker and TOM-601) under greenhouse conditions. A randomized complete block design was used with three replications. Infestations with T. absoluta adults were performed weekly and the following characteristics were evaluated: number of small, large and total mines/leaf and % of leaves mined at days 60, 75 and 90 after planting. Low infestation occurred at days 60 and 75 but at day 90, infestation was sufficient to evaluate insect damage. Based on these data it was concluded that only accessions HGB-674 and HGB-1497 appeared to be the most promising. In addition, to determine possible chemical causes of resistance, hexane extracts were analyzed at day 90 by gas chromatography/mass spectrometry and the major peaks identified by a mass spectral database using similarity index. Nine hydrocarbons, viz., hexadecane, heptadecane, eicosane, tricosane, 2-methyltricosane, tetracosane, hexacosane, octacosane and triacontane were identified in the hexane extracts in many samples. Tricosane, tetracosane and hexacosane presented significant correlations with the leaves mined. Only tricosane presented a negative correlation with the number of small mines (r = −0.28), total number of mines (r = −0.27) and % of leaves mined (r = −0.22). However, tetracosane and hexacosane presented significant positive correlations (r = 0.25 and 0.24, respectively) with the % of leaves mined.  相似文献   
8.
Unharvested stubbles or harvested straw of rice (Oryza sativa L.) gets incorporated into soil and interferes with the seedling growth of crop plants. In this paper, we investigated whether rice straw, either through releasing allelochemicals and/or through manipulating soil properties, influences seedling growth of Phalaris minor Retz., a non-native weed largely restricted to wheat (Triticum aestivum L.) fields. One hundred twenty grams of soil was amended with rice straw (0.5, 1, 2, 4, or 6 g/pot) and its effect on fresh shoot biomass of P. minor was examined. Any modification of rice straw phytotoxicity through the use of washed rice straw, activated charcoal, soil sterilization, or nitrogen fertilization was also studied. We carried out chemical and microbial analysis of soils to examine the role of soil properties in influencing P. minor growth. Incorporation of rice straw into soil suppressed the growth of P. minor through modifying soil properties. A dose-dependent increase in total phenolics was observed in soil amended with rice straw. Activated carbon or washing of rice straw, however, could not ameliorate the phytotoxic effects of rice straw. Our results provide initial evidence that rice straw restricts P. minor growth by manipulating soil chemical and microbiological properties. Authors contributions IJ conceived of and supervised the study, and wrote the paper; SK carried out the work.  相似文献   
9.
植物化感物质及其释放途径   总被引:20,自引:2,他引:18  
生物体产生生物活性物质即化感物质在生物体之间传递信息并导致生物体相互作用,这称为化感作用。植物化感作用的研究近年来十分活跃,化感作用物质主要来自植物的次生代谢产物。该文介绍了化感作用的定义、化感物质种类及化感物质释放的途径  相似文献   
10.
室内和田间试验表明:麦秸的水浸提物对玉米的胚芽和胚根的生长有显著影响作用。小麦-玉米轮作区免耕覆盖的土壤中可以检测到4种酚酸:阿魏酸、香草酸、肉桂酸和对羟基苯甲酸,它们在土壤中的平均含量分别为(2.62~4.94)×10-5,(5.72~7.54)×10-5,(3.05~5.38)×10-5和(3.93~5.20)×10-5mol/L。它们在土壤中下降的速度很慢。室内检测阿魏酸、香草酸和对羟基苯甲酸抑制玉米的胚芽和胚根的生长,其抑制根伸长10%的浓度(ED10)分别是1.14,3.57和6.30mmol/L。  相似文献   
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