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。

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。

云南不同入侵地区的加拿大一枝黄花表型观测分析

旨在明确加拿大一枝黄花在云南省11个不同发生地区的生态适应性。在同质园条件下分别观测其植物性状及差异。试验可以看出,不同入侵地区发生的加拿大一枝黄花,在同质园条件下进一步的生长、繁殖特征差异显著,其中根萌芽性状指数的变异幅度达到了54.23%,茎秆直径、叶宽和叶形指数变异幅度为23.63%~26.31%。在生物量分配比中,花生物量分配占比最高的植株来自文山州丘北县,叶生物量分配占比最高的植株来自昆明西山区,茎秆生物量分配占比最高的植株来自昆明盘龙区,根部生物量分配占比最高的同样来自昆明盘龙区。进一步测定加拿大一枝黄花POD、SOD、CAT、MDA酶活,来自11个不同入侵地区和生境的植株群体表现出显著差异,其中以文山州丘北点和昆明盘龙点的加拿大一枝黄花植株的茎秆、株高和酶活等性状表现较为突出。通过聚类分析发现植物性状中叶表现出一定差异性,但在气候因子的偏相关性分析中发现,原始地的气候因子对加拿大一枝黄花的影响较小。结果表明,加拿大一枝黄花的植物性状基本稳定一致,但不同入侵地区由于环境条件的不同,表型具有一定差异和可塑性。研究结果对明确该加拿大一枝黄花在云南省的生态适应性奠定重要科学基础,同时为预警、监测及防范该入侵植物的扩展提供科学依据。

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。

基于Maxent和ArcGIS加拿大一枝黄花适生区预测

为了研究加拿大一枝黄花在中国的适生区及其分布影响因素,以利于有效防控,采用最大熵模型(Maxent)和ArcGIS软件对加拿大一枝黄花2041—2060、2061—2080气候模式下在中国的潜在适生区进行预测。结果显示:当前适生区预测AUC值为0.933,模型预测结果理想;适生区分布主要受气温和降水影响;潜在适生区主要分布在华东和华中地区,以上海市全域、江苏省中南部、安徽省中部、江西省北部、湖南省东部、湖北省东部以及浙江省部分地区和沿海海岸线为主。随着时间推移,2041—2060年相比较于当前,高、中适生区的面积增加106.04万km^(2),低适生区增加110.62万km^(2);2061—2080年,高、中适生区的面积与当前相比增加110.99万km^(2),低适生区增加111.55万km^(2)。总体来说,未来气候变化下,加拿大一枝黄花的适生区呈现出不断扩张的趋势,建议相关部门基于其潜在适生区的变化趋势制定响应的分级管理策略,以防止进一步扩散。

加拿大一枝黄花在贵州省黔东南地区的入侵现状与风险分析

为掌握加拿大一枝黄花Solidago canadensis L.在贵州省黔东南地区的发生情况和风险等级,并提出防控策略,防止其进一步快速传播扩散。2022年1月至11月通过走访调查,分析和研究加拿大一枝黄花在贵州省黔东南地区的入侵及分布情况,运用林业有害生物风险分析指标体系开展了定量分析评估。结果表明,加拿大一枝黄花于2015年首次入侵黔东南,7年间扩散到境内14个县41个乡镇,其风险综合评价值R为2.58。加拿大一枝黄花在黔东南地区呈多点分布,处于定殖阶段,部分点分布面积大,属于特别危险风险等级。针对加拿大一枝黄花在黔东南地区的发生分布情况,本研究提出了监测、防治等风险管理措施。

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.

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.

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 cy19:0 to 18:1ω7 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 18:1ω7c,16:1ω7t,16:1ω5c and 18:2ω6,9 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 of Solidago canadensis L.

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.

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.

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.

Hairy Root Cultures and Plant Regeneration in <i>Solidago nemoralis</i>Transformed with <i>Agrobacterium rhizogenes</i>

By screening a native plant extract library we identified Solidago nemoralis as a novel source of agonists for alpha7 nicotinic receptors for acetylcholine with therapeutic potential. The next phase of our drug discovery strategy is to increase the yields of active compounds in the plant species by gain of function mutations in hairy root cultures [1]. Here we report a protocol for Agrobacterium rhizogenes-mediated genetic transformation of hairy root cultures of Solidago nemoralis which will enable this. Leaf explants of this species were successfully transformed with a frequency of 30%-35% using A. rhizogenes strain R1000 harboring the binary vector pCambia 1301. Transformation was confirmed using the β-glucuronidase (GUS) histochemical assay. Transformed hairy roots showed spontaneous regeneration of adventitious shoots in media without the addition of cytokines, albeit at very low frequency. However, media supplementation with auxin (α-naphthaleneacetic acid, NAA) increased shoot regeneration frequency to 35% and resulted in viable adventitious shoots. Transformation was confirmed at all phases of plant regeneration by GUS staining. Hairy root transformation of Solidago altissima has been previously reported, but this is the first report of genetic transformation of S. nemoralis. The protocol will allow for a large population of activation tagged mutants of S. nemoralis to be generated which will be then screened for the presence of stable mutants which are over-producing metabolites with activity at alpha7 nicotinic receptors. These over-producing mutant cultures will then be regenerated into intact mutant plants.

外来入侵植物加拿大一枝黄花的研究进展与资源化利用策略

加拿大一枝黄花Solidago canadensis Lour现已入侵至包括中国在内的亚洲大部分国家、欧洲中西部国家,以及澳大利亚和新西兰等地,成为一种世界性入侵杂草,严重影响各区域的生态结构、生态安全和环境。在中药资源化学理论的指导下,基于中药及天然药物资源的多宜性原则,在前人较为系统的研究基础上,针对性地提出采用“化害为利”策略,引导和促进这一外来入侵物种的转化利用,将其归化为可造福于我国经济社会和生态健康发展的特色优势资源,为促进人与自然和谐共生、丰富我国中药及天然药物资源种类做出应有贡献。

南京市加拿大一枝黄花入侵地群落的物种组成与多样性特征研究

为探究外来植物加拿大一枝黄花(Solidago canadensis)入侵与南京市本土植物多样性的关系,该文采用踏查及样方调查对其入侵地群落的物种组成与多样性进行研究。结果表明:(1)入侵地群落中共有维管植物200种(含种下单元),隶属于62科156属,其中被子植物195种,裸子植物1种,蕨类植物4种;数量最多的是菊科(Asteraceae)和禾本科(Poaceae)植物,分别有25种和24种;从生活型来看,草本植物占多数,有133种,占所有种的66.50%;此外,群落内尚有其他外来植物29种。群落中重要值最大的是加拿大一枝黄花,为40.00%;其次是救荒野豌豆(Vicia sativa),为7.00%。(2)从植物区系看,非入侵地中植物科的区系分布型共4个,而入侵地植物科的区系类型仅有3个,其中泛热带分布、世界分布和北温带分布为两者均有,东亚和北美间断分布型仅在非入侵地中存在。非入侵地植物科的区系以世界分布型为主,有13科,占该类型群落中所有科的39.39%;入侵地则以泛热带分布型为主,有16科,占总科数的45.71%。非入侵地中植物属的区系分布型有10个,而入侵地有12个,两者区系成分相近,旧世界热带型和热带亚洲至热带大洋洲分布型仅在入侵地中出现。北温带分布型和世界分布型同为两者中最主要成分。入侵地及非入侵地群落属的区系R/T值分别为0.58和0.38,种系分化度分别为3.29和3.11。(3)重度入侵群落的Margalef指数(E)与非入侵及轻度入侵群落相比,显著降低;此外,重度入侵群落的Simpson指数(D)、Shannon-Weiner(H′)指数和Pielou指数(J)均显著低于非入侵、轻度入侵、中度入侵群落。(4)不同生境之间加拿大一枝黄花群落的E、D、H′和J均无显著性差异。该研究可为南京地区的加拿大一枝黄花入侵地的治理防控和生态恢复,以及进一步的科学研究提供强有力的理论支撑。

加拿大一枝黄花高效防治的物理与化学技术筛选

【目的】筛选出对防治加拿大一枝黄花高效且对生态环境影响较小的防治方法。【方法】以入侵至江西省的加拿大一枝黄花为试验材料,选用2个物理处理、8个化学处理防治措施,每个措施4个生物学重复,处理前调查样方中加拿大一枝黄花总株数、株高,处理后通过设定样方考查每个防治处理加拿大一枝黄花的死亡株数、株高、校正株防效和鲜重防效。【结果】物理处理中,刈割+翻耕+碎土处理15~60 d后,进贤、九江两处试验地加拿大一枝黄花再生植株的平均密度(15.33株/m^(2)和21.00株/m^(2))均极显著远小于刈割处理(204.33株/m^(2)和85.33株/m^(2))。化学处理中,30%草甘膦异丙胺盐+75%甲嘧磺隆可湿性粉剂和21%氨氯吡啶酸能够有效防治加拿大一枝黄花。处理60d后,进贤、九江两处试验地加拿大一枝黄花的死亡率达到100%,且没有再生苗;校正株防效均达到100%,地上与地下鲜重防效分别在63%、70%以上;根部的根状茎及营养细根均坏死、萎缩腐烂;处理一年后仍没有加拿大一枝黄花再生,且21%氨氯吡啶酸对环境的毒副作用更小。而其它6组药剂均不能彻底防除加拿大一枝黄花,处理60d后,加拿大一枝黄花的死亡率未能达到100%,且有再生苗冒出;校正株防效未能达到100%,地上与地下鲜重防效分别在50%~85%和10%~76%;根部未死亡且均有新芽冒出。【结论】大面积防治加拿大一枝黄花使用化学药剂21%氨氯吡啶酸,可达到最好的防治效果,且持续时间久,对生态环境负面影响最小;在荒地可采取地面割除+翻耕+碎土的复耕方法,也能够有效地防治加拿大一枝黄花。

加拿大一枝黄花总黄酮对尖孢镰刀菌生长抑制效果的研究

为探究加拿大一枝黄花Solidago canadensis(Linnaeus)总黄酮对尖孢镰刀菌Fusarium oxysporum生长的抑制效果,采用超声法从加拿大一枝黄花花序中提取总黄酮并设定7个处理(0~18 mg/mL),测定其对尖孢镰刀菌甜瓜专化型F.oxysporum f.sp.melonis FOM生长、生理指标的影响及田间防治效果。结果表明:加拿大一枝黄花总黄酮浓度为18 mg/mL时,FOM孢子萌发抑制率达到100.00%;菌丝断裂、畸变;FOM的OD650和pH最小,分别为0.18和3.5;其电导率增大,是对照组的1.3倍。此外,加拿大一枝黄花总黄酮处理24 h后,FOM的超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性均呈现先上升后下降趋势,18 mg/mL处理组SOD和CAT活性在48 h降至最低,分别为24.69和19.00 U/mL。大田试验结果表明:样区受试作物酥瓜Cucumis melo死亡株数与加拿大一枝黄花总黄酮处理浓度成负效应,表明较高浓度的加拿大一枝黄花总黄酮浇灌重茬种植甜瓜的土壤,可有效抑制FOM生长,减少FOM的致病性。因此,该研究可为合理开发加拿大一枝黄花资源及发展新型绿色植物源FOM防治剂提供理论参考。