鸡眼草水浸提液对4种草坪草的化感作用

为探讨鸡眼草(Kummerowia striata)不同部位、不同浓度水浸提液对高羊茅(Festuca arundinacea)、黑麦草(Lolium perenne)、狗牙根(Cynodon dactylon)、白三叶(Trifolium repens)等4种草坪草的化感效应和作用规律,采用培养皿纸床法,以蒸馏水为对照,研究鸡眼草剪碎的植株、未剪碎的植株、叶、茎、根、地上部分0.012 5、0.025、0.05 g/mL 3个不同浓度的水浸提液对高羊茅、黑麦草、狗牙根、白三叶的种子发芽率、发芽速率、幼根长、幼苗高的化感作用。结果表明,鸡眼草水浸提液对高羊茅、黑麦草、狗牙根、白三叶4种受体植物种子的萌发及幼苗生长均有较强的化感抑制作用,且对种子发芽率作用强弱顺序为:狗牙根白三叶黑麦草高羊茅,对种子发芽速率作用强弱顺序为:黑麦草高羊茅狗牙根白三叶,对幼苗苗高作用强弱顺序为:黑麦草白三叶狗牙根高羊茅,对幼苗根长作用强弱顺序为:白三叶黑麦草狗牙根高羊茅。对4种受体植物的综合化感效应以高羊茅最弱,黑麦草、狗牙根、白三叶较为相近。4种受体植物所受到的抑制作用均随着水浸提液浓度的增加而增强,在同一浓度不同部位水浸提液处理下,叶、整株(剪碎)水浸提液对4种受体植物抑制作用比根、茎、整株(未剪碎)及地上部分水浸提液强。高羊茅、黑麦草、狗牙根3种草坪草受0.05 g/mL鸡眼草叶水浸提液的化感抑制作用最强,白三叶则受0.05 g/mL鸡眼草整株(剪碎)水浸提液的化感抑制作用最强。     

加拿大一枝黄花根系和根际土壤水浸液对萝卜和白菜种子萌发及幼苗生长的影响

用加拿大一枝黄花根系及根际土壤水浸液对白菜和萝卜的化感作用进行了研究。结果表明,加拿大一枝黄花根系水浸液和根际土壤水浸液对白菜和萝卜种子的萌发具有抑制作用。根际土壤水浸液对白策和萝卜幼苗生长具有促进作用,而对其胚根的伸长生长则具有显著的抑制作用。0．05g／mL根系水浸液处理显著抑制萝卜幼根的伸长,但其它浓度对白菜和萝卜幼苗生长和根系伸长的影响不明显。实验还表明高浓度的根系水浸液和根际土壤水浸液明显抑制白菜和萝卜的根系脱氢酶活性和硝酸还原酶活性。     

豚草的化感作用研究

本文研究了在我国东北地区广泛蔓延的菊科杂草－－豚草对大豆、玉米、小麦、水稻的化感作用,实验针对豚草的挥发物、茎叶和根的淋溶物、根区土壤水浸液等的化感活性进行了研究,研究发现豚草的挥发物对大豆和玉米的种子萌发有一定抑制作用,根区土壤对农作物无明显的作用;茎叶部分的水浸液对几种农作物的种子萌发和幼苗的幼根伸长有明显的抑制作用,同时使根系形态发生较大的变化,根系的水浸液对作物的幼芽伸长有一定的促进作用。     

外来杂草反枝苋对农作物的化感作用及其风险评价

利用改进的差时播种共培法,以麦田伴生恶性杂草播娘蒿为对照,在实验室条件下研究反枝苋根系分泌物及其不同浓度残枝浸提液对小麦、玉米、油菜种子萌发及生长的影响.结果显示:(1)反枝苋幼苗的根系分泌物能够显著抑制作物根长和苗高的生长;(2)反枝苋不同浓度浸提液均能抑制作物种子的萌发,其抑制作用随浓度的增加而增强;(3)除0.025 g·mL-1处理对小麦根长和苗高、玉米苗高有促进作用外,其余各浓度反枝苋浸提液对作物幼苗的根长和苗高有不同程度的抑制,且对根长的抑制作用更强;(4)反枝苋对作物幼苗的抑制作用强于恶性杂草播娘蒿,风险评估定量分析结果认定反枝苋为陕西省高度危险性植物.     

骆驼蓬提取物对玉米种子α-淀粉酶和根系活力的影响

用开花期多裂骆驼蓬地上部分的乙醇提取物水溶液对玉米种子浸种20h后,在室内常规培养,并在不同时间测定种子萌发率及其α-淀粉酶活性、幼苗根系活力及幼苗培养14d时根系和茎叶的干重。结果表明,浸种处理对种子萌发及种子α-淀粉酶活性有抑制作用,且提取物水溶液浓度越高,萌发率和酶活性越低;浸种能增加幼苗根系活力,显著提高幼苗生物产量,其作用随提取物水溶液浓度的提高开始增加,然后下降。     

根际区他感化学物质的分离、鉴定与生物活性的研究

本文报道根际区他感化学物质对小麦、玉米等作物种子萌发及幼苗生长抑制作用的研究结果。土壤及土壤溶液样品提取物,用ＧＣ及ＧＣ－ＭＳ鉴定出各类化合物５０多种。重点研究有代表性的３种化合物：十四烯－１、苯甲醛以及未见报道的,由作者鉴定了贩他感化合物：对－叔丁基苯甲酸。结果表明,十四烯－１在浓度达２０００ｍｇ／ｌ时,对玉米、小麦、田菁、稗子的种子萌发,幼根及幼芽生长均无明显影响;苯甲醛浓度在２００ｍｇ／ｌ以     

油蒿挥发油的化感作用研究

对毛乌素沙地油蒿挥发油的化感作用（Ａｌｅｌｏｐａｔｈｙ）及其化学成分进行了研究。结果表明：油蒿挥发油对苋、诸葛菜、萝卜种子萌发和幼苗生长具有不同程度的抑制作用;对小麦种子萌发几乎无影响,但对其幼芽和幼根的生长具一定影响。抑制作用最强的是对苋种子,挥发油组最终萌发率１８％,比对照组减少７１％,对其幼芽和幼根的生长影响也很明显。用ＧＣ、ＧＣ－ＭＳ－ＤＳ联用方法,共鉴定４３个化合物,其中相对百分含量在１．５％以上的化合物有如下１４种：１）α－蒎烯（α－ｐｉｎｅｎｅ）,２）桧烯（Ｓａｂｉｎｅｎｅ）,３）β－蒎烯（β－ｐｉｎｅｎｅ）,４）月桂烯（Ｍｙｒｃｅｎｅ）,５）对伞花烃（ρ－ｃｙｍｅｎｅ）,６）柠檬烯（Ｌｉｍｏｎｅｎｅ）,７）β－水芹烯（β－ｐｈｅｌａｎ－ｄｒｅｎｅ）,８）β－顺式罗勒烯（β－ｃｉｓ－ｏｃｉｍｅｎｅ）,９）β－反式罗勒烯（β－ｔｒａｎｓ－ｏｃｉｍｅｎｅ）,１０）松油烯－４－醇（Ｔｅｒｐｉｎｅｎ－４－ｏｌ）,１１）α－姜黄烯（α－ｃｕｒｃｕｍｅｎｅ）,１２）茵陈炔（Ｃａｐｉｌｅｎｅ）,１３）橙花叔醇（Ｎｅｒｏｌｉｄｏｌ）,１４）匙叶桉油烯醇（Ｓｐａｔｈｕｌｅｎｏｌ）。     

苦豆子的抗生成分

苦豆子茎叶水提取液对小麦幼芽、幼根的生长表现出明显的抑制作用。水溶液含有苦豆碱,槐定和槐果碱。实验表明,当这些生物碱作用于小麦幼苗时,引起强烈的抑制作用,结果如下:(1)苦豆子水提取液对小麦幼苗的生长有强烈的抑制作用,对幼芽的最低抑制浓度为5％,对幼根的最低抑制浓度为0.1％。(2)薄层层析实验表明,水溶液中苦豆碱、槐定和槐果碱为主要抑制成分,它们可被小麦幼根吸收,但不能传入幼芽中。(3)苦豆碱的抑制作用大于槐定和槐果碱。它们的最低抑制浓度分别为8.6×10~(-5) M、2.0×10~(-3)和2.0×10~(-3)至8.1×10~(-4)M。3种生物碱对幼根的抑制作用大于对幼芽的抑制作用。(4)根据含量测定,在相同浓度作用下,苦豆碱在小麦幼根根尖中的含量均比槐定和槐果碱高,表明苦豆碱容易被小麦幼根吸收。同时,苦豆碱的毒性大于槐定和槐果碱。     

小飞蓬提取物除草活性的生物测定

以高粱(Sorghum vulgarePers.)、黄瓜(Cucum is sativusL.)、小麦(Triticum aestivumL.)和油菜(BrassicacampestrisL.)为供试对象,用种子萌发法测定了小飞蓬(Erigeron canadensisL.)全株的石油醚、乙酸乙酯和乙醇等3种溶剂提取物的除草活性。小飞蓬的乙酸乙酯与乙醇提取物对4种供试作物均显示出很强的抑制生长作用,浓度达100 mg.mL-1时对小麦和油菜幼苗生长的抑制率均为100%。小飞蓬乙酸乙酯提取物对高粱和油菜的幼根及黄瓜和油菜幼茎的生长有明显的抑制作用。低浓度乙醇提取物对小麦和高粱幼根及幼茎的生长有较强抑制作用,但高浓度时则对黄瓜和油菜的抑制作用较强;6.25 mg.mL-1乙醇提取物对黄瓜、油菜、小麦和高粱幼茎生长的抑制率分别为6.50%、8.58%、21.51%和26.98%;25 mg.mL-1乙醇提取物的抑制率则分别达到61.31%、77.45%、39.78%和46.34%。表明小飞蓬乙酸乙酯和乙醇提取物具有潜在的除草活性。     

入侵杂草加拿大一枝黄花的化感作用

测定了加拿大一枝黄花水浸提液对辣椒、番茄、萝卜、长梗白菜和小麦等五种经济作物种子萌发和生长的影响。结果表明:(1)高浓度的加拿大一枝黄花水浸提液对几种作物种子萌发和生长有明显的抑制作用,而低浓度下则对萝卜、长梗白菜和番茄的种子生长有一定的促进作用;(2)加拿大一枝黄花茎叶部分水浸提液的抑制作用要强于地下部分。     

模拟氮沉降对杂草生长和氮吸收的影响

以杂草早熟禾、黑麦草、野燕麦、天蓝苜蓿、白车轴草、北美车前、婆婆纳、无芒稗、牛筋草和刺苋为试验材料,以4.0g·m^-2·yr^-1的N输入为模拟氮沉降浓度,研究了不同杂草功能类群对模拟氮沉降的响应.结果表明,模拟氮沉降处理下,杂草的生物量(总生物量、地上部分生物量、根生物量)呈增加趋势,但不同功能类群对氮增加的响应明显不同,C₄禾本科、C₃豆科及C₃禾本科植物的生物量受到氮沉降的显著促进,但C₃非禾本科和C₄非禾本科植物的生物量则受氮沉降的影响不显著;不同功能类群的根冠比、植株含氮及植株吸收氮的总量对模拟氮沉降的响应无明显规律,但物种间差异显著.氮沉降提高野燕麦和北美车前的生物量的根冠比,但对其他生物种类没有显著影响.没有发现氮沉降对植物体内的含氮量有显著的影响,但氮沉降却显著地提高了除刺苋、早熟禾及婆婆纳之外的所有杂草物种对N的摄收.由于物种对氮沉降的响应不同,未来氮沉降的增加将加速杂草群落组成的变化.     

模拟铅污染土壤中杂草的菌根形成及对铅的吸收

通过盆栽试验研究了13种杂草在模拟铅污染土壤中的菌根形成及对铅的吸收累积特点。结果表明铅污染对杂草的生长没有明显影响。铅污染土壤中杂草的菌根侵染状况发生了显著变化,与无污染的土壤相比,苦荬菜(Ixerischinensis)、早熟禾(Poaannua)、黑麦草(Loliumperenne)、野燕麦(Avenafatua)、野豌豆(Viciacracca)、白车轴草(Trifoliumrepens)的菌根侵染率下降,而无芒稗(Echinochloacrusgallivar.mitis)、北美车前(Plantagovirginica)、鼠曲草(Gnaphaliumaffine)和酢浆草(Oxaliscorniculata)的菌根侵染率上升,鸡眼草(Kummerowiastriata)、升马唐(Digitariaciliaris)和婆婆纳(Veronicadidyma)无明显变化;土壤中的孢子数除了鸡眼草、野豌豆、白车轴草和酢浆草无显著差异外,其余物种在铅污染土壤中的孢子数量与对照相比明显下降。不同的杂草物种对土壤铅的吸收和积累存在明显差异,被杂草吸收的铅主要积累在杂草根系内,向杂草地上部转移的铅比率不高。     

Models analyses for allelopathic effects of chicory at equivalent coupling of nitrogen supply and pH level on F. arundinacea, T. repens and M. sativa

Alllelopathic potential of chicory was investigated by evaluating its effect on seed germination, soluble sugar, malondialdehyde (MDA) and the chlorophyll content of three target plants species (Festuca arundinacea, Trifolium repens and Medicago sativa). The secretion of allelochemicals was regulated by keeping the donor plant (chicory) separate from the three target plant species and using different pH and nitrogen levels. Leachates from donor pots with different pH levels and nitrogen concentrations continuously irrigated the target pots containing the seedlings. The allelopathic effects of the chicory at equivalent coupling of nitrogen supply and pH level on the three target plants species were explored via models analyses. The results suggested a positive effect of nitrogen supply and pH level on allelochemical secretion from chicory plants. The nitrogen supply and pH level were located at a rectangular area defined by 149 to 168 mg/l nitrogen supply combining 4.95 to 7.0 pH value and point located at nitrogen supply 177 mg/l, pH 6.33 when they were in equivalent coupling effects; whereas the inhibitory effects of equivalent coupling nitrogen supply and pH level were located at rectangular area defined by 125 to 131 mg/l nitrogen supply combining 6.71 to 6.88 pH value and two points respectively located at nitrogen supply 180 mg/l with pH 6.38 and nitrogen supply 166 mg/l with pH 7.59. Aqueous extracts of chicory fleshy roots and leaves accompanied by treatment at different sand pH values and nitrogen concentrations influenced germination, seedling growth, soluble sugar, MDA and chlorophyll of F. arundinacea, T. repens and M. sativa. Additionally, we determined the phenolics contents of root and leaf aqueous extracts, which were 0.104% and 0.044% on average, respectively.     

Infection with the fungal endophyte Epichloë festucae may alter the allelopathic potential of red fescue

Red fescue (Festuca rubra) is a perennial grass used as both forage and turfgrass. Asymptomatic plants of this species are systemically infected by the fungal endophyte Epichloë festucae, which has a beneficial effect on the infected plants. The aim of this study was to determine the effect of the endophyte Epichloë festucae on the allelopathic potential of F. rubra against four associated pasture species that are also considered as weeds in lawns, Trifolium pratense, Trifolium repens, Lotus corniculatus and Plantago lanceolata. Two experiments were designed to evaluate the allelopathic effect of extracts from the roots and leaves of endophyte‐infected (E+) and non‐infected (E?) plants on the germination and seedling growth of the four target species. Regardless of the endophyte status of the host plant, leaf extracts elicited a stronger reduction in germination and seedling growth than root extracts. Extracts from E+ plants reduced the speed of germination index of Trifolium spp. to a greater extent than those from E? plants. Radicle length of the target species was the parameter most affected by the presence of the endophyte in F. rubra. Root extracts from E+ plants had a greater inhibitory effect on the radicle growth of the target species than did root extracts from E? plants. A greater concentration in total phenolic compounds was found in the roots of E+ plants than of E?; however, this difference was not observed in the leaves. Thus, the allelopathic potential of F. rubra is altered in infected plants.     

小蓬草水浸液对2种花卉种子萌发及幼苗生长的化感作用北大核心CSCD

为揭示入侵杂草与草本花卉之间的竞争关系,以入侵植物小蓬草为供体材料,常用的花卉波斯菊、观赏油菜为受体材料,研究了小蓬草根、叶水浸提液对受体植物种子萌发、幼苗生长、抗氧化酶活性(SOD、POD和CAT)以及丙二醛(MDA)含量的化感效应差异。结果表明,(1)小蓬草浸提液对受体植物的种子萌发均具有显著化感效应,基本表现为“低促高抑”的趋势,且波斯菊、观赏油菜的种子萌发率在根、叶浸提液浓度为25 g/L时最高,在浸提液浓度为100 g/L时最低。(2)小蓬草浸提液对受体植物幼苗上下胚轴生长具有“低促高抑”的浓度效应,且浓度越大抑制作用越显著。(3)在小蓬草根、叶浸提液处理下,观赏油菜的SOD和POD活性大多显著高于对照,波斯菊SOD和POD活性则大多显著低于对照;波斯菊、观赏油菜CAT活性整体呈先缓慢升高后降低的趋势。(4)波斯菊幼苗MDA含量随小蓬草根、叶浸提液浓度的增加均呈现逐渐升高的趋势,并大多高于对照水平,而观赏油菜幼苗MDA含量随着根浸提液浓度增加而逐渐升高,却随着叶浸提液浓度的增加而降低,但大多显著低于对照水平。研究发现,小蓬草浸提液对2种花卉种子萌发和幼苗生长均表现出“低促高抑”化感作用,且综合效应强弱表现为观赏油菜大于波斯菊,根浸提液处理大于叶浸提液。     

Allelopathic interactions between invasive plant Solidago canadensis and native plant Phragmites australis

Taking the seeds of invasive plant Solidago canadensis and native plant Phragmites australis from their mono- and co-dominant communities as allelopathic acceptors, this paper analyzed the differences in the seed germination rate and sprout length after treated with five level (12.5, 25, 50, 100, and 200 mg x mL(-1)) S. canadensis and P. australis extracts, aimed to understand the allelopathic interactions between the two species. The 1000-grain weight and seed germination rate under distilled water treatment of the two species in co-dominated community were greater than those in mono-dominant community. Low level (12.5 and 25 mg x mL(-1)) S. canadensi extracts slightly promoted the seed germination rates of S. canadensis in both mono- and co-dominant communities, but high level (50, 100, and 200 mg x mL(-1)) S. canadensi extracts had strong inhibition effect, especially for the S. canadensis in co-dominated community. No significant patterns were observed about the effects of P. australis extract on S. canadensis seed germination. The sprout length of S. canadensis seeds in both mono- and co-dominant communities decreased with increasing level of S. canadensis extract, but decreased in a fluctuation way with increasing level of P. australis extract. After treated with the extracts of P. australis or S. canadensis, the seed germination rate of P. australis in mono-dominant community was significantly greater than that in co-dominant community (P < 0.05), but there was no significant difference between these two extracts.     

Assessment of the Allelopathic Potential of Ageratum Conyzoides

The allelopathic potential of Ageratum conyzoides, which is one of the most dominant weeds in upland-crop areas of Southeast Asia, was investigated under laboratory conditions. The residue obtained from an aqueous acetone extract of the plant shoots inhibited the germination and the growth of roots and shoots of Amaranthus caudatus, Digitaria sanguinalis and Lactuca sativa. The concentration-dependent responses of the test plants suggest that the residue of Ageratum conyzoides might contain allelochemical(s).     

废橡胶颗粒浸提液物质释放及其浸种对草坪植物生长的影响

纯胶粒浸提液、胶粒与壤土混合的浸提液中重金属含量分析表明,纯胶粒浸提液中Zn含量最高,其次为Pb,而Cd与Cu最少;与纯胶粒浸提液相比,胶粒与壤土混合的浸提液中Zn含量显著降低.紫外吸收光谱图显示,胶粒粒径越小,浸提液中有机物越复杂.用4种不同粒径胶粒的浸提液对2种草坪植物种子浸种处理后进行培养,研究了草坪植物的生长效应.结果表明,胶粒浸提液浸种对2种草坪植物的种子萌发率影响不大,但对株高产生不同的影响.对黑麦草而言,以2～4 mm胶粒浸提液浸种的株高为最高,1～2和4～6 mm胶粒浸提液浸种株高与之差异较大,分别降低1.52和1.32 cm,但均与对照无显著差异.对于高羊茅,以粒径1～2 mm胶粒浸提液浸种的株高为最低,比对照降低了18.76%,其它处理间无明显差异.浸提液浸种对黑麦草地下生物量有明显的抑制作用,但对根长生长有促进作用.胶粒浸提液浸种对2种草坪植物的地上生物量无明显影响.从胶粒浸提液的物质释放及其浸种对草坪植物生长的影响来看,废胶粒可用于运动场草坪的基质组配.     

Enhanced allelopathy and competitive ability of invasive plant Solidago canadensis in its introduced range

Aims Why invasive plants are more competitive in their introduced range than native range is still an unanswered question in plant invasion ecology. Here, we used the model invasive plant Solidago canadensis to test a hypothesis that enhanced production of allelopathic compounds results in greater competitive ability of invasive plants in the invaded range rather than in the native range. We also examined the degree to which the allelopathy contributes increased competitive ability of S. canadensis in the invaded range.Methods We compared allelochemical production by S. canadensis growing in its native area (the USA) and invaded area (China) and also by populations that were collected from the two countries and grown together in a 'common garden' greenhouse experiment. We also tested the allelopathic effects of S. canadensis collected from either the USA or China on the germination of Kummerowia striata (a native plant in China). Finally, we conducted a common garden, greenhouse experiment in which K. striata was grown in monoculture or with S. canadensis from the USA or China to test the effects of allelopathy on plant–plant competition with suitable controls such as adding activated carbon to the soil to absorb the allelochemicals and thereby eliminating any corresponding allopathic effects.Important findings Allelochemical contents (total phenolics, total flavones and total saponins) and allelopathic effects were greater in S. canadensis sampled from China than those from the USA as demonstrated in a field survey and a common garden experiment. Inhibition of K. striata germination using S. canadensis extracts or previously grown in soil was greater using samples from China than from the USA. The competitive ability of S. canadensis against K. striata was also greater for plants originating from China than those from the USA. Allelopathy could explain about 46% of the difference. These findings demonstrated that S. canadensis has evolved to be more allelopathic and competitive in the introduced range and that allelopathy significantly contributes to increased competitiveness for this invasive species.     

薇甘菊的化感作用研究

研究薇甘菊对萝卜、黑麦草、白三叶以及薇甘菊常见伴生树种马占相思、马尾松、大叶桉的生化他感作用。分别用薇甘菊地上部分、根部、枯枝叶和土壤的水提液以及地上部分的石油醚、乙酸乙酯和乙醇提取液按照一定浓度进行生物测定。研究表明,薇甘菊地上部分水提液能够显著影响受体植物生长,根水提液的抑制作用程度稍低,其枯枝叶水提液基本无作用。薇甘菊地上部分的石油醚和乙醇提取物均对受体植物幼苗生长表现出一定的抑制作用．但是乙酸乙酯提取物的作用最强烈,可使种子发芽过程受阻,幼苗生长受抑制程度高达90％以上．显示化感物质主要集中在这一部分。