Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.)

It is less known whether and how soil metal lead （Pb） impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species （Solidago canadensis L.） in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal （AM） fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels （control, 300, and 600 mg/kg soil） were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species （ Glomus mosseae, Glomus versiform, Glomus diaphanum, Glomus geosporum, and Glomus etunicatum）. The ^15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants. The results showed that S. canadensis was highly dependent on mycorrhizae. The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization （root length colonized, RLC%） but did not affect spore numbers, N （including total N and ^15N） and P uptake. The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments. The Pb was mostly sequestered in belowground of plant （root and rhizome）. The results suggest that the high efficiency of mycorrhizae on nutrient uptake might give S. canadensis a great advantage over native species in Pb polluted soils.

Application and Characterization of Cellulose Acetate Membrane Produced from Herbaceous Plant: Solidago Canadensis L.

In this work,the viability of Solidago Canadensis L. for cellulose acetate membrane production was tested. The cellulose was extracted from Solidago Canadensis L. stem by organic solvents,and the cellulose diacetate was obtained by acetylization of cellulose. The properties of the intermediate products of cellulose pulp and cellulose diacetate were characterized by FT-IR and XRD. Compared with commercial cellulose diacetate,the properties of cellulose diacetate were similar to those of the commercial cellulose diacetate. The cellulose acetate membrane with desirable pure water flux and rejection rate was obtained from cellulose diacetate by solution casting. The membrane showed favorable hydrophilic property so that it had good anti-pollution performance. The maximum pure water flux of the membrane was 27. 21 m L /( cm2· h) and the maximum rejection rate was 80. 39%. The results demonstrated that the membrane obtained from herbaceous plant: Solidago Canadensis L. had good performance of ultrafiltration.

加拿大一枝黄花(Solidago canadensis L.)水浸提液对小麦的化感作用及机制

为了阐明加拿大一枝黄花(Solidago canadensis L.)对小麦的化感作用机制,研究了加拿大一枝黄花新鲜茎叶的水浸提液对小麦(Triticum aestivum)种子萌发和幼苗生长的影响,以及对小麦种子中α-淀粉酶活性、叶片中脂质过氧化作用及根系活力的影响。整个试验在完全随机情况下进行,一组质量浓度0.025、0.05和0.1 g·mL-1水浸提液用于对小麦化感作用的研究,在此基础上,设置另一组质量浓度0.01、0.02和0.03 g·mL-1水浸提液用于作用机制随水浸提液处理7和14 d时的变化研究,均用蒸馏水作空白对照。结果表明:在水浸提液质量浓度为0.025、0.05和0.10 g·mL-1时,加拿大一枝黄花水浸提液对小麦种子萌发和幼苗生长表现出很强的抑制作用,而且抑制强度随水浸提液质量浓度的增加而增强。水浸提液抑制小麦种子α-淀粉酶的活性,0.03 g·mL-1时达到显著水平(P<0.05)。水浸提液处理小麦7 d后,小麦叶片中SOD、POD和CAT活性均受到抑制,MDA含量显著升高,作用强度随水浸提液质量浓度的增加而增强。处理14 d后,SOD与CAT活性呈现出不规律性波动,MDA含量仍呈上升趋势,总体水平低于7 d时的试验结果;POD活性呈下降趋势,但与对照无显著差异,总体水平高于7 d时的试验结果。水浸提液处理后,小麦根系活力升高,随着处理时间延长,根系活力有所下降。结论:加拿大一枝黄花水浸提液对小麦种子萌发的抑制作用与α-淀粉酶活性的变化有关,对小麦幼苗生长的抑制作用与脂质过氧化作用和根系活力的变化有关。

Allelopathic effects of extracts from Solidago canadensis L. against seed germination and seedling growth of some plants

To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous and ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepared and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry （Morus alba）; morning glory （Pharbitis nil）, wheat （Triticum aestivum） and rape （Brassiea campestris）. Reduction and/or growth in germination and growth of the target plant species in the presence of both aqueous and ethanolic extracts at different concentrations indicated that the responses were species-specific and concentration-dependent. Generally, ethanolic extracts （especially from leaves） imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.001 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulberry. It is suggested that the aqueous and ethanolic extracts of all the three parts of S. canadensis have significant allelopathic effects. Although both inhibition and stimulation occurred in the germination and growth of the target species, extracts with higher concentrations definitely inhibit seed germination and seedling growth of all target plants. We suggest that allelopathy plays a more important role than other mechanisms do in the out-competition ofS. canadensis over other plants, and make it invasive in new habitats.

Changes of Soil Microbiological Characteristics After Solidago canadensis L. Invasion

The relationship between Solidago canadensis L. invasion and soil microbial communities was studied across the invasive gradients varying from 0 to 40, 80, and 100% coverage of S. canadensis. The results showed both soil microbial biomass C （Cmic） and N （Nmic） increased as the coverage of S. canadensis increased. Soil microbial quotient Cmic/Corg （microbial biomass C/organic C） tended to increase linearly with the coverage of S. canadensis. Soil basal respiration （BR） also showed a similar trend. The soil respiratory quotient qCO2 decreased with S. canadensis invasion, and remained at quite a constantly low level in the invasive soils. Sole carbon source utilization profiles analyses indicated that S. canadensis invasion tended to result in higher microbial functional diversity in the soil. Average utilization of specific substrate guilds was highest in the soil with S. canadensis monoculture. Principle component analysis of sole carbon source utilization profiles further indicated that microbial functional diversity in the soil with S. canadensis monoculture was distinctly separated from those soils in the native area and the ecotones. In conclusion, S. canadensis invasion improved soil microbial biomass, respiration and utilization of carbon sources, and decreased qCO2, thus created better soil conditions, which in turn were more conducive to the growth of S. canadensis.

Joint toxic effects of heavy metals and atrazine on invasive plant species Solidago Canadensis L.

In this study, the joint effects of Cd(Ⅱ), Pb(Ⅱ) and atrazine (ATR) on Solidago Canadensis L. were investigated. The results showed that soil containing Cd, Pb and ATR could inhibit root elongation of Solidago Canadensis L., and that there was a positive linear relationship between the inhibitory rate of root elongation and the concentrations of Pb(Ⅱ). The mixture of Cd(Ⅱ) and Pb(Ⅱ)-ATR in soil showed a significant adverse effect on root and shoot biomass of Solidago Canadensis L. Acetylsalicylic acid (ASA) contents increased slightly at the lower concentrations of Cd(Ⅱ)-ATR, then decreased when Cd(Ⅱ)-ATR concentrations were higher than those of 1.0 TUmix(Cd+ATR). The toxic effect of Pb(Ⅱ)-ATR on the ASA contents of Solidago Canadensis L. was greater than that of Cd(Ⅱ)-ATR. Soluble sugar contents firstly decreased and then increased with increasing concentrations of Cd(Ⅱ)-ATR and displayed fluctuation with increasing concentrations of Pb(Ⅱ)-ATR. Total protein contents in-creased with increasing concentrations of Cd(Ⅱ) and Pb(Ⅱ)-ATR , relative to the control sample. The NP-SH con-tents showed a significant increase up to 12.2 mg/gfw of Cd(Ⅱ)-ATR, followed by a significant decline to 4.5 mg/gfw after 14 days of exposure. The effect of Pb(Ⅱ)-ATR was similar to that of Cd(Ⅱ)-ATR but the amount of NP-SH was not higher than that of Cd(Ⅱ)-ATR.

加拿大一枝黄花(SolidagocanadensisL.)不同水浸液对作物种子发芽和生长的影响

分别采用2种方法获取加拿大一枝黄花的根茎和叶水浸液,对小麦、大麦、玉米、水稻、番茄和油菜等6种作物的种子进行发芽率测定,并对小麦、玉米和水稻3种作物幼苗进行生长量试验。结果表明:各水浸液对6种作物的种子萌发均有明显的抑制作用,水稻、小麦和玉米3种作物的幼苗生长受到影响,处理间差异显著。根茎和叶粉碎液的不同浓度对玉米的生长影响不同,浓度越高影响越大,各浓度处理间的差异显著。

外来植物加拿大一枝黄花(Solidago canadensis)入侵的结构基础

采用野外观察、光镜、扫描电镜等手段,对入侵皖北的加拿大一枝黄花形态解剖结构进行了研究,并藉此理解该物种入侵适应的结构基础。结果表明:叶的上、下表皮的气孔数目均较少,具有厚的角质层和长的表皮毛,能起到保水和保护作用;叶片内有发达维管束和束鞘延伸,增加了叶片对光合产物的输导能力,以满足地下营养器官发育的需要。茎具有较强输导和支持能力的结构特征。主根过早停止发育,以适应地下逸生结构发育的需要。加拿大一枝黄花花期、花序结构和未能与本地昆虫建立固定访问关系使部分头状花序不育,成熟花粉粒外有胼胝质包被,有利于花粉传播,其花粉粒属于较为进化的类型;根状茎含较多菊糖,具备成为独立散布体的物质和结构基础。

日本菟丝子(Cuscuta japonica)寄生对加拿大一枝黄花(Solidago canadensis)生理生态特性的影响

调查发现，野外有日本菟丝子（Cuscuta japonica）寄生于加拿大一枝黄花（Solidago canadensis）植株的现象，被寄生的加拿大一枝黄花植株矮小，叶片枯黄，生长严重受阻。在实验控制条件下，观测了日本菟丝子寄生后加拿大一枝黄花生理生态特性的相关指标，并对寄主进行了解剖观察，探讨了应用日本菟丝子防除加拿大一枝黄花的可行性。结果表明：（1）日本菟丝子可以寄生于加拿大一枝黄花的茎及叶片，寄生根能够穿过加拿大一枝黄花表皮、皮层直至髓部，从寄主植株吸收水分和养分，使自身生物量得到增加，并严重影响了寄主的生长；（2）寄生50～60d后，被寄生植株最大光合速率只有对照的58．81％，而光合补偿点则为对照的153．39％；脯氨酸和丙二醛含量分别为对照的2．88和1．29倍，可溶性蛋白、可溶性总糖含量则分别下降了43．45％、44．47％；（3）金华地区，自然条件下生长的加拿大一枝黄花一般在9月中旬现蕾，10月中旬进入盛花期，而被寄生植株直到10月下旬才开始现蕾，花序长度不到正常植株的10％，当菟丝子生物量（干重）超过加拿大一枝黄花植株的13．14％时该植株不能开花结实。从实验结果看，日本菟丝子寄生可以严重影响加拿大一枝黄花的营养生长和开花结实。因此，利用日本菟丝子有望成为防治加拿大一枝黄花危害的一种辅助手段。

Characteristics of soil microbial community functional and structure diversity with coverage of Solidago Canadensis L

The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.

浙江省加拿大一枝黄花(Solidago canadensis)的空间分布格局及其与人类活动的关系

原产于北美的加拿大一枝黄花目前正在我国境内尤其是东部地区迅速扩散,对当地的社会经济、自然生态系统和生物多样性构成了严重威胁。应用G IS技术揭示了2005年浙江省加拿大一枝黄花发生面积和发生面积比例的空间分布格局,并结合回归统计方法,分析了该空间分布格局与人类活动的关系。结果表明:加拿大一枝黄花在浙江省的分布存在明显的空间异质性;进口货物总额与农业活动强度是解释加拿大一枝黄花发生面积变异的主要因子;境内公路里程是解释加拿大一枝黄花发生面积比例变异的主要因子。在大力发展经济的同时,不能忽视经济发展对生态环境产生的负面影响,如物种入侵。对于加拿大一枝黄花的防控,应加大对抛荒地和闲置地的复垦力度,从源头上控制其发生面积。

Warming and elevated nitrogen deposition accelerate the invasion process of Solidago canadensis L.

Background:Invasive species can threaten native diversity and alter ecosystem processes while interacting with other components of global environmental change.Invasive plants are becoming increasingly problematic and this can be stimulated by changes in the environment.However,existing studies have primarily investigated the effects of environmental change on a specific stage of plant invasion rather than the continuous invasion process.Methods:A space-for-time substitution experiment was performed to investigate how warming and nitrogen deposition affects the invasion process of a plant.Specifically,different ratios of invasive Solidago canadensis L.to native Artemisia argyi Levl.et Van were employed as a proxy to represent successive levels of invasion.A total of seven treatments were applied in the experiment:ambient(CK),N addition(+5,+12 g m^(−2)year^(−1)),warming(+1.15,+1.86℃)and their interaction(5 g N m^(−2)year^(−1)+1.15℃,12 g N m^(−2)year^(−1)+1.86℃).The growth performance and competitiveness of S.canadensis were investigated.Results:The competitiveness of Solidago canadensis decreased linearly with its invasion degree(p<0.05).Non-linear regression showed that S.canadensis invasion levels of 53%,53%,68%,55%and 58%were the critical thresholds for shifting the direction or magnitude of chlorophyll,leaf nitrogen,leaf shape index,diameter,and root/shoot ratio,respectively.Compared with the ambient treatment(CK,no warming and no N addition),the diameter,height,bio-mass and relative competitiveness of S.canadensis were each limited by warming,to a certain extent,whereas these and the above parameters were significantly increased by nitrogen deposition.The interaction of increased temperature and nitrogen deposition led to significant increases in the growth and competitiveness of S.canadensis,and this effect was detected in every stage of the invasion,throughout the invasion process.Conclusions:Environmental change might have a continuous,progressive,and augmentative effect on the phenotypic traits of S.canadensis.This study provides fairly robust evidence that environmental change promotes the invasion process of S.canadensis in general,not simply in specific stages.In the future,rather than focusing on specific stages,experimental studies should consider examining invasion on a broader scale.

Development of Granule Composition Based on the Total Evaporated Extract of Bidens Tripartita, Solidago Canadensis and Agrimonia Eupatoria Herbs

The aim of the study is the development and standardization of granules in hard gelatin capsules based on the composition of dry extracts of Bidens tripartita L.,Solidago canadensis L.and Agrimonia eupatoria L.Herbs,possessing nephroprotective activity and antifibrotics in toxic nephropathies.Developed the structure and defined the quality indicators of the pellets with dry extracts of Bidens tripartita L.,Solidago canadensis L.and Agrimonia eupatoria L.herbs.The quality specification for the drug-granules of the composition of dry extracts in solid gelatin capsules is developed.

2-Steps Preparation Activated Carbon from Solidago Canadensis:Carbonized by Electrial heating and Activated by Microwave Radiation

The activated carbon(AC)was prepared from Solidago Canadensis(SC),an alien invasive plant.The plant was firstly carbonized under nitrogen at 400 ℃ for 90 min in an electrical furnace,and then the carbonized product was activated with KOH through microwave radiation.Effects of KOH/C ratio,microwave power,microwave radiation time on the adsorption capacities and yield of AC were evaluated.It indicated that the optimum conditions were KOH/C ratio 2 g/g,microwave power 700 W,and microwave radiation time 6 min.The carbonation process of SC was analyzed by thermogravimetry(TG).The pore structural parameters and surface functional groups of the AC were characterized by nitrogen adsorption-desorption and Fourier Transformed Infrared Spectroscopy(FTIR),respectively.The activation yield,the surface area,the average pore size,and the average micropore size of AC prepared from optimum conditions were 53.75%,1 888 m2/g,0.567 nm,and 0.488 nm,respectively.The adsorption amounts of AC were 302.4 mg/g for methylene blue and 1 470.27 mg/g for iodine.

Is root nutrient uptake a modular function? A test using Solidago canadensis

Plant roots have been recognized to be modu- lar, and a third order root cluster has been proposed to be the basic root module unit based upon the life cycle. This experiment examines root modularity of the nutrient-up- take function using stable isotope 15N. Solidago canadensis root clusters of second or third orders--from the same third or fourth order roots, respectively--were treated with 15NH15NO3, NH4NO3, and de-ionized water for 15 and 180 min. The δ15N values of the root clusters were then analyzed and compared. The 15N values of 15N-treated root clusters of both second and third orders were hundreds of times higher than that of the 15N untreated root clusters. However, the differences of the δ15N values among 15N untreated root clusters （though expressed some significant variations）, did not indicate the 15N shared by the sister root clusters came from a common higher-order root. These results demonstrated functional modularity of root nutrient uptake, revealed a second order root, perhaps even a first order root to be a base module unit in terms of root nutrient uptake. The results also suggested that the concept of root modularity is function-specific. This experiment further revealed the importance of treatment timing in stabilizing the internal 15N/14N ratio in roots and avoiding top-down transportation of 15N back into roots to secure unbiased measurements.

入侵植物加拿大飞蓬(Erigeron canadensis L.)生理生态适应初探

利用PEG-6000模拟根际干旱胁迫法,研究了入侵植物加拿大飞蓬(Erigeron canadensis L.)在水分胁迫下的生理生态变化.在干旱胁迫下,加拿大飞蓬体内的丙二醛(MDA)、脯氨酸(Pro)含量、过氧化物酶(POD)酶活、超氧化物酶(SOD)酶活以及可溶性蛋白含量均发生了不同程度的变化.在不同胁迫强度下,MDA含量、Pro含量、可溶性蛋白含量和POD酶活均呈现上升趋势;在胁迫初期,加拿大飞蓬体内SOD酶活呈现上升趋势,胁迫中期出现下降趋势,后期又呈现出明显的上升趋势,表明其体内抗旱机制多种多样,能够适应多种生境.

Occurrence of Glyphosate-Resistant Horseweed (Conyza canadensis) Population in China

Horseweed （Conyza canadensis）, an invasive alien weed, is one of the main weeds in orchards in China. Although glyphosate has been used for control of horseweed and many other weeds in orchards for more than 25 years in China, a case of glyphosate-resistant horseweed has not been identified in orchard in China so far despite glyphosate-resistant horseweed cases have been reported in some other countries. Seeds of 25 horseweed populations were collected from different orchards with different glyphosate application history. Potted seedlings with 11-13-leaf growth stage were treated with glyphosate at 0.035, 0.07, 0.14, 0.28, 0.56, 1.12, 2.24, 4.48, and 8.96 kg a.i. ha-1. The dosage dependence response curve of each population was constructed with Log-logistic dose response regression equations. The ED50 value of each population was calculated and compared with the susceptible population from China. Different populations had different relative glyphosate-resistant levels which increased with the number of years of glyphosate application. Two populations with the highest resistance levels, 8.28 and 7.95 times, were found in Ningbo, Zhejiang Province, China, where glyphosate was used for weed control in orchards twice each year for 15 yr. The two resistant populations accumulated approximately two to four times less shikimic acid than the two susceptible populations 48 h after glyphosate application.

Chemical Constituents from Mentha haplocalyx Briq.(Mentha canadensis L.)and Theirα‑Glucosidase Inhibitory Activities

Mentha haplocalyx(Mentha canadensis)is widely used as a medicinal plant in traditional Chinese medicine,and the extracts of its aerial parts are found to signifcantly inhibit the activity ofα-glucosidase with an IC_(50) value of 21.0μg/mL.Bioactivity-guided isolation of the extracts aforded two new compounds(1 and 2),together with 23 known ones(3-25).Their structures were established by extensive spectroscopic analyses(1D and 2D NMR,MS,IR and UV).Compounds 1-17 and 21-25 were evaluated for theirα-glucosidase inhibitory activities.Compound 11 was the most active ones with an IC_(50) values of 83.4μM.These results verify theα-glucosidase inhibitory activity of M.haplocalyx(M.canadensis)and specify its active compounds for the frst time.

Effects of Water Extract of Erigeron canadensis L. on Seed Germination of Plants

[Objective] The paper was to explore the effect of water extract of Erigeron canadensis L. on seed germination of plants. [Method] Using constant temperature culture method, the effects of water extracts of roots, stems and leaves of E. canadensis on seed germination of 14 species of test plants （crops and weeds） were studied. [Result] Water extracts of roots, stems and leaves of E. canadensis had obvious inhibition effect on seed germination of test plants. The water extract of leaves had the strongest inhibition effect, which could completely inhibit the seed germination of Crepis tectorum L., Amaranthus tricolor L. and Chrysanthemum coronarium L. under the lower concentrations of 0.050 and 0.075 g/ml, and completely inhibit seed germination of all the plants under the concentration of 0.400 g/ml except Zea maize L. and Allium fistulosum L.; followed by water extract of stems, and the water extract of roots had the lowest the inhibition effect, except for completely restraining seed germination of Lycopersicum esculentum L. under the concentration of 0.300 g/ml, it still could not completely restrain seed germination of the other plants under the highest concentration of 0.500 g/ml. The inhibition effect of water extract of E. canadensis on seed germination of plants had obvious selectivity, which had more obvious effect on dicotyledonous plants than monocotyledonous plants. [Conclusion] The study provided reference for screening and utilization of allelochemicals of E. canadensis and research on its allelopathy mechanism.

加拿大一枝黄花白绢病(Sclerotium rolfsii)菌株SC64的生物学特性研究

在实验室条件下初步研究了加拿大一枝黄花白绢病菌株SC64的形态特征、致病性和生物学特性。结果表明:引起加拿大一枝黄花白绢病的病原物是罗氏白绢小菌核菌(Sclerotium rolfsii Sacc.);病菌最适生长培养基为Richard固体培养基和PDA,菌丝生长温度为15～40℃,最适30℃;在偏酸性条件下生长较好,生长适宜pH值为4.0～6.0,最适为5.0;在所测试的碳源中,对蔗糖的利用最好,对乳糖和半乳糖利用最差;氮源测试结果显示对蛋白胨和硝酸钾利用最好,对尿素的利用最差。菌核萌发温度为15～40℃,最适为30℃;菌核在含水量≥50%的麸皮基质上萌发较好;适宜萌发的pH值范围为3.0～9.0。菌丝的致死温度为45℃10 min,菌核的抑制萌发温度为50℃10 min。