党参和黄芪种植地土壤水浸液对玉米化感作用研究

为了探讨中草药党参和黄芪根际土壤水浸液对玉米的化感作用,采用生物测定方法,研究了中草药党参和黄芪根际土壤水浸液0.5、0.25、0.12 gmL和0.062 5 g/mL 4个浓度梯度对玉米种子萌发及幼苗生长的影响.结果表明,2种中药根际土壤水浸液对受体玉米种子吸胀过程中相对吸水量的增加有抑制作用,抑制程度随其浓度的升高而增强;玉米种子萌发和幼苗生长的化感效应在低浓度为表现为化感促进作用,在高浓度为表现化感抑制作用,对玉米幼苗渗透调节物质可溶性糖、MDA和Pro含量都有显著影响.种植地土壤水浸液对玉米的化感效应由强到弱依次为:党参和黄芪＞黄芪＞党参.     

紫茉莉种子水浸液对西瓜和枸杞的化感作用研究

采用室内生物测定法,研究了紫茉莉种子水浸液对西瓜、枸杞种子萌发和幼苗生长的影响,以期为植物化感作用的理论研究提供参考。结果表明,不同浓度紫茉莉种子水浸液对西瓜种子萌发和幼苗生长表现为化感抑制作用,而对枸杞种子萌发,幼苗苗高、鲜重、根鲜重表现为化感促进作用,且表现为浓度效应。     

蜀葵种子水浸液对西瓜和枸杞的化感作用

研究蜀葵种子水浸液对西瓜和枸杞的化感作用,为植物化感作用的理论研究提供参考。采用生物测定法,用不同浓度的蜀葵种子水浸液处理西瓜、枸杞的种子和幼苗,研究其化感作用。结果表明：（1）不同浓度的蜀葵种子水浸液对西瓜种子萌发和幼苗生长均有不同程度的抑制作用,对枸杞幼苗的苗高、鲜重有促进作用;（2）当蜀葵种子水浸液浓度为0.005 g/mL、0.010 g/mL时对枸杞种子萌发和幼苗生长表现为化感促进作用,浓度为0.020 g/mL时对枸杞种子的发芽率、幼苗根长、根鲜重表现为化感抑制作用。综上,蜀葵种子水浸液可抑制西瓜种子的萌发和幼苗的生长,对枸杞幼苗的苗高、鲜重的增加有促进作用。     

棉花水浸提液对西瓜、大豆的化感作用研究

为探究"瓜、棉、豆"套作体系在农业生产中可行性利用的生理基础,通过盆栽试验,研究陆地棉根部水浸提液对白菜、西瓜和大豆种子萌发及幼苗生长的化感效应。结果表明:100 g·L~(-1)的棉花根部浸提液原液,显著抑制了3种作物的种子萌发。稀释4倍的根部水浸提液对白菜种子萌发的抑制作用显著,萌发率相比水处理下降了10.54%,但该浓度下大豆、京欣西瓜和新小玉西瓜的种子萌发率分别为86.6%、86.7%和87.53%,对比水处理无显著变化。原液浓度的棉花根部浸提液极显著抑制了白菜幼苗的生长,并使白菜植株体内的SOD、POD和CAT等保护酶活性显著下降,大豆和西瓜的POD等保护酶活性并无显著影响。不同浓度的棉花根系浸提液对白菜和大豆表现出低浓度促进而高浓度抑制现象,不同浓度的棉花根系浸提液对西瓜表现出低浓度促进而高浓度不抑制现象。     

黄花蒿对绿豆种子萌发及幼苗生长的化感效应

以绿豆种子为受体,采用室内生测法,探讨黄花蒿不同部位水浸提液对绿豆种子的萌发率、幼苗生长及叶绿素含量的影响。结果表明:黄花蒿各部位(根、茎、叶)水浸提液随处理浓度增加,对绿豆的化感效应增强,对种子萌发的抑制强弱为:叶>茎>根,且随处理浓度升高,发芽率降低;对幼苗的根系生长表现为低浓度(20mg/mL根、茎水浸提液)促进,当浓度高达40mg/mL均有明显抑制作用;幼苗高度总体降低,最高降幅分别为46.29%,47.67%和56.48%;叶绿素a和叶绿素b的含量也不同程度减少。可见黄花蒿影响绿豆种子萌发及幼苗生长,因此大面积栽培黄花蒿或绿豆种植应考虑黄花蒿的化感效应。     

丁香酸和阿魏酸对大豆种子萌发及幼苗生长的影响

以“中黄13”大豆为材料,研究处理液浓度分别为100,200,300,500 mg/L的阿魏酸和丁香酸对大豆种子萌发及幼苗生长的影响.结果表明,2种化感物质不同浓度处理液对大豆种子萌发及幼苗生长均能够产生显著的化感效应.4种浓度的阿魏酸处理液对大豆种子萌发均表现出抑制作用.浓度为500mg/L的阿魏酸抑制效果最为显著.较低浓度(100,200,300mg/L)的丁香酸处理液对大豆种子发芽率未表现出明显的影响,却推迟了种子萌发,显著降低了种子的发芽势和发芽指数.浓度为500mg/L的丁香酸显著抑制了大豆种子萌发.阿魏酸和丁香酸对大豆幼苗鲜重、根长、株高具有抑制作用,且抑制作用随处理浓度的增加而增强.4种处理浓度的阿魏酸和丁香酸均使大豆幼苗中的MDA含量增加,叶绿素含量降低,使大豆幼苗下表皮气孔长度减小,打开的气孔个数减少,气孔数目增多.     

空心莲子草化感效应的初步研究

测定空心莲子草(Alternanthera philoxeroides Griseb)地上部和地下部水浸提液对小麦和油菜种子萌发、幼苗生长和一些生理过程的影响,研究空心莲子草的化感作用及其机理。结果显示,空心莲子草水浸提液对小麦种子萌发过程的影响主要表现在延迟发芽,而对最终萌发率影响不大;在油菜种子的萌发过程中,高浓度的水浸提液延迟了种子发芽,同时影响最终萌发率;在低浓度空心莲子草水浸提液的影响下,小麦幼苗植株生长增加,高浓度地下部分水浸提液则抑制了小麦幼苗根和苗的生长;在油菜幼苗的生长过程中,空心莲子草水浸提液均抑制了油菜幼苗的生长;另外,空心莲子草水浸提液处理过程中,小麦和油菜体内的超氧化物歧酶(SOD)活性和过氧化物酶(POD)活性均有显著变化。     

朝仓花椒叶水浸提物对白菜种子萌发及幼苗生长的影响

就朝仓花椒(Zanthoxylum piperitum DC.var.inerme Makino)叶水浸提物对4种白菜种子萌发和幼苗生长的影响进行了研究.结果表明,花椒叶水浸提物显著抑制白菜种子萌发和幼苗生长,且水浸提液浓度越高,抑制作用越强.水浸提液稀释4倍,白菜幼苗生长仍受到显著抑制,过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性均显著降低,丙二醛(MDA)含量显著增高.说明白菜萌发及幼苗生长受到抑制是由于白菜幼苗的酶系统遭受破坏所致.     

火炬树根和凋落叶水浸提液对小麦种子萌发的化感作用

研究了不同浓度(10%、5%、2.5%和1.7%)的火炬树(Rhus typhina)根和凋落叶水浸提液对小麦种子萌发的化感作用.结果表明:2种器官水浸提液对小麦种子萌发均具有强烈的化感抑制作用,表现为萌发率、萌发指数、幼苗活力指数的降低和萌发进程的延迟(萌发速率系数增大),而且具有明显的浓度作用:火炬树凋落叶水浸提液对小麦种子萌发的化感作用强于根的化感作用;火炬树根和凋落叶水浸提液对小麦种子萌发指数的化感作用最强,对幼苗活力指数的化感作用次之,对萌发速率系数的化感作用最弱.     

阔叶丰花草水浸提液对5种作物的化感作用

采用室内生物测定方法研究不同浓度的阔叶丰花草水浸提液对5种作物(西瓜、水稻、萝卜、辣椒和番茄)种子萌发和幼苗生长的化感影响.结果表明:不同浓度的阔叶丰花草水浸提液对5种作物种子的发芽率、幼苗茎长和根长均有较强的化感作用,并且随着浸提液浓度的升高,化感效应明显增强.当浸提液浓度为0.05 g/mL时,5种受体作物的化感综合效应强弱顺序为西瓜＞萝卜＞水稻＞番茄＞辣椒.其根部比茎部的化感作用更敏感,受到的抑制作用更强,但对辣椒和番茄的茎表现出了一定的促进作用.     

Assessing Allelopathic Index for Estimating Allelopathic potential of Ajowan Extracts

Allelopathy is a procedure in which secondary metabolites are produced by plants. Some plants may beneficially or antagonistically affect other plants through allelochemical compounds which may be released directly or indirectly from live or dead parts and cause allelopathic and phytotoxic effects. The aim of the present study was to investigate the allelopathic possibility of ajowan (Carum copticum) extracts in different concentrations on morphological indices (germination and growth) of wheat (Triticum sativum), barley (Hurdeum vulgare), corn (Zea maize S.C 704), and safflower (Carthamus tinctorius L.) seedlings as proceeding crops and to develop a comprehensive formula for measuring the negative and positive effects of allelochemicals on growth indices such as shoot and root length, as well as the germination percentage on donor plants. It was demonstrated that increasing concentrations of ajowan extracts significantly decreased the Allelopathic Index, percent of germination, and other growth related indices of all seedlings. Based on the proposed Allelopathic Index of experimental plants, it was revealed that ajowan has posed a higher risk to corn and barley especially at the early stages of the growing cycle, while safflower and wheat indicated more tolerance to growth inhibition effects of ajowan in rotational sequence.     

不同浓度的辣椒化感物质对莴苣化感效应研究

以莴苣为试材,通过辣椒植株水浸液、水浸液醇溶组分和根系分泌3种方法收集化感物质,研究了不同浓度的化感物质对莴苣的化感效应。结果表明,3种方法收集的化感物质对莴苣均表现为高控低促的化感浓度效应,并且对根部生长的影响远大于地上部,不同生长时期的莴苣对化感物质的敏感度不同,苗期比发芽期敏感。     

Allelopathic Effect of Three Serious Weeds of Nigerian Savanna on Germination and Seedling Vigour of Soybean and Maize

Allelopathic effects of aqueous extract of three weeds, Ageratum conyzoides L., Imperata cylindrica (L.) Beauv and Commelina benghalensis L. of Nigerian savanna were investigated on the germination and seedling vigour of soybean ( Glycine max [L.] Merr.) and maize ( Zea mays L.). Aqueous extracts of these weeds exhibited allelopathic phenomenon on seed germination and seedling vigour. Aqueous extracts of I. cylindrica and C. benghalensis at 1 % and 5 % concentration (w/v) had stimulatory effect on soybean germination as against inhibitory effect of 10 % aqueous extract of all weeds on the germination of both soybean and maize seeds. Seedling vigour-length of roots and shoots and fresh weight of seedlings were promoted by aqueous extract of A. conyzoides up to 5 % concentration in soybean whereas all concentrations of extract stimulated the seedling vigour of maize. Aqueous extract of I. cylindrica up to 5 % also caused stimulatory effect on the seedling vigour of both crops but such effects were lesser in magnitude than that observed in case of A. conyzoides. On the contrary, the aqueous extract of C. benghalensis at all concentrations resulted in deleterious effect on the seedling vigour of both soybean and maize.     

Allelopathic Effects of Parthenium hysterophorus Extracts on Seed Germination and Seedling Growth of Eragrostis tef

The present study was conducted to investigate the allelopathic effects of Parthenium hysterophorus weed on seed germination and seedling growth of tef. Flower, stem, root and leaf aqueous extracts of Parthenium at 0, 1, 5, and 10 % concentrations were applied to determine their effect on tef seed germination and seedling growth under laboratory conditions. Increasing concentrations of aqueous extracts of Parthenium from leaf and flower inhibited seed germination and complete failure of seed germination was recorded when the extract concentration from the leaf part was 10 %. In contrast, aqueous extracts from stem and root had no effect on tef seed germination. Roots appeared more sensitive to allelopathic effect than shoots. Extracts from flower, root and stem had a stimulatory effect on shoot length at all concentration levels, as against an inhibitory effect of leaf extracts. Root extracts at low concentration (1 %) greatly promoted root length but aqueous extracts from leaf and flower inhibited root length.     

入侵植物斑地锦浸提液对几种蔬菜的化感作用研究

为了深入理解斑地锦对入侵地作物的危害及其入侵机制,本研究用蒸馏水浸提斑地锦茎叶内地有效成分,以番茄、辣椒、苋菜和荆芥为受体,利用培养皿滤纸法研究斑地锦浸提液对种子萌发和幼苗生长的影响。结果表明,斑地锦浸提液可降低四种蔬菜种子的发芽速率,抑制番茄、辣椒和荆芥的发芽率,并且这种抑制作用随处理浓度的提高而加强,而对苋菜种子的发芽率无显著影响;0.4 g/ml的斑地锦浸提液强烈抑制了四种蔬菜根的生长,却不同程度地促进了辣椒、荆芥和苋菜茎的生长,对根/茎比的影响与对种子发芽率的影响类似。     

红景天果皮水提液对5种植物种子的化感作用

以狭叶红景天种子、榆荞种子、樱桃番茄种子、意大利耐抽薹生菜种子和新牛角椒种子为受试材料,研究了狭叶红景天果皮水提液对5种植物的化感作用.结果表明,不同浓度的狭叶红景天果皮水提液对5种植物种子的萌发、胚根及幼苗生长均表现出不同的化感作用影响.其中,对狭叶红景天种子萌发和胚根生长都表现为明显的抑制作用,并且随着处理浓度增高,抑制作用表现越强,但对幼苗的生长却表现出明显的促进生长作用,其中以0.02 g/mL的水浸液处理的狭叶红景天幼苗生长速度最快;对榆荞种子萌发和幼苗生长表现为低浓度促进生长和高浓度抑制生长的作用,而对胚根生长却表现抑制作用,并随着处理浓度的增高,抑制作用也越强;对樱桃番茄和意大利耐抽薹生菜种子的萌发和胚根生长也都表现为明显的抑制作用,对樱桃番茄幼苗的生长影响与榆荞的一致,对意大利耐抽薹生菜幼苗的生长影响与狭叶红景天植物一致;对新牛角椒种子萌发的影响与榆荞种子相同,对其胚根和幼苗生长影响都表现为促进作用,但也存在随着处理浓度增高,其产生的促进生长作用逐渐减弱的现象.     

小麦秸秆不同部位水浸液对牛筋草的化感作用研究

通过室内生物测定法研究了小麦秸秆的不同部位（根、茎、穗）不同浓度水浸液（6.25,12.5,25,50,100mg?mL-1）对牛筋草种子萌发和幼苗生长的化感作用,结果表明：小麦秸秆根、茎、穗部水浸液对牛筋草种子的萌发均具有抑制作用,随着浓度的升高,牛筋草发芽率逐渐降低,发芽指数逐渐减少,以最高浓度100mg?mL-1水浸液抑制作用最强,不同部位水浸液处理的牛筋草发芽率依次为对照（84.5%）＞根（71.3%）＞茎（68.7%）＞穗（58.7%）,发芽指数依次为对照（18.39）＞根（12.82）＞茎（6.77）＞穗（6.07）。根部水浸液对牛筋草苗高无显著影响,茎、穗部水浸液只有在最高浓度处理下显著抑制其幼苗高度,但是对根部生长均表现出“低促高抑”作用,当根、茎、穗部水浸液浓度为6.25mg?mL-1时,牛筋草根长分别比对照增加17.1%,17.8%及6.6%,而当其浓度为100mg?mL-1时,牛筋草根长分别比对照降低25.6%、31.6%及95.6%。通过拟合剂量-效应曲线得到小麦秸秆根、茎及穗部水浸液对牛筋草根部生长的半数效应浓度EC50值分别为219.182,157.545及41.007mg?mL-1     

玉米、小麦秸秆水浸提液对蔬菜种子的化感作用

以黄瓜、生菜、茄子种子为受试材料,采用室内生物测定方法研究了玉米、小麦秸秆水浸提液的化感作用.结果表明,作物秸秆对蔬菜种子的影响有抑制、促进、促进/抑制双重作用和无显著作用等多种形式.玉米水浸提液对黄瓜种子活力指数、幼苗根长和鲜质量显著抑制,对苗高和干质量表现低浓度促进高浓度抑制;对生菜、茄子种子的发芽和根系生长显著抑制,对苗高和鲜质量均表现促进/抑制双重作用.小麦秸秆水浸提液对黄瓜苗高、鲜质量表现促进作用;对生菜种子活力指数和幼苗根长具有显著抑制作用,对其苗高和鲜质量均表现促进/抑制双重作用;对茄子发芽率显著抑制作用,对其根长、苗高和鲜质量均表现双重作用.根据化感敏感指数,玉米秸秆水浸提液对受体蔬菜的化感作用强于小麦;生菜对秸秆浸提液最敏感,茄子次之,黄瓜最不敏感.     

Herbicidal Potential and Quantification of Suspected Allelochemicals from Four Grass Crop Extracts

Unknown compounds in crop plants are inhibitory to seed germination and early seedling growth of weed plants. A Petri dish assay showed that barley (Hordeum vulgare L.), oats (Avena sativa L.), rice (Oryza sativa L.) and wheat (Triticum aestivum L.) extracts significantly reduced root growth of alfalfa (Medicago sativa L.), barnyard grass (Echinochloa crus‐galli, Beauv. var. oryzicola Ohwi.) and eclipta (Eclipta prostrata L.). As the concentration of crop extracts increased, root growth of the test plants were significantly reduced. A high‐performance liquid chromatography analysis with nine standard phenolic compounds showed that the concentrations and compositions of allelopathic compounds depend on the extracted plant extracts. Caffeic acid, hydro‐cinnamic acid, ferulic acid, m‐coumaric acid, p‐coumaric acid and coumarin were present in all the crop plant species, and hydro‐cinnamic acid were detected as the highest amount. Coumarin at 10^?3 m significantly inhibited root growth of alfalfa and barnyard grass more than that of eclipta. The research suggests that extracts of barley, oats, rice and wheat have an allelopathic effect on alfalfa, barnyard grass and eclipta and that the findings of bioassay were considerably correlated with the type and amount of causative allelochemicals, indicating that the allelopathic effects on three test plants were ranked in order of wheat (highest), barley, rice and oats (lowest). The results may have value in enabling weed control based on natural plant extracts or crop residues in the fields.     

银胶菊根际土壤化感作用的初步研究

研究银胶菊根际土壤浸提液对蔬菜种子和幼苗的化感作用。采用水浸提法制备不同浓度的银胶菊根际土壤浸提液,用生物测定法测定其对上海青、甜菜、苋菜种子萌发和幼苗生长的化感效应。银胶菊不同浓度土壤浸提液对3种植物种子萌发总体具有抑制作用,但对甜菜的GI表现为促进作用,同一浓度的土壤浸提液对3种植物种子发芽率的抑制作用大小顺序为苋菜>上海青>甜菜。与对照相比,幼苗根长和苗高发生明显变化;游离脯氨酸含量均高于对照,且随浸提液处理浓度的增加呈现升高趋势,而可溶性糖含量变化的趋势不一致。银胶菊根际土壤浸提液具有一定的的化感效应,且对不同植物及不同生长特性的化感效应具有选择性。