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题名	外来入侵植物意大利苍耳的化感作用
作者	邰凤姣
学位类别	硕士
答辩日期	2015
授予单位	中国科学院大学
授予地点	北京
导师	张元明 ; 邵华
关键词	意大利苍耳，化感作用，挥发油，土壤微生物，土壤酶，土壤养分
学位专业	理学硕士
中文摘要	意大利苍耳(Xanthium italicum Moretti)原产于美洲，为一年生菊科植物，主要依靠种子传播，一株发育良好的植株可以结出1400多颗种子，从而促进了它的繁衍和传播。我国于1991年9月首次在北京发现，现已广泛分布于我国的东北、华北、西北地区。意大利苍耳主要危害玉米、棉花、大豆等农作物，对我国农业生产造成了重大的经济损失。本文研究不同部位意大利苍耳挥发油对受试植物的化感作用、入侵地土壤微生物群落结构功能、土壤酶活性和土壤养分含量的变化情况、对受试植物生长发育的影响，对进一步了解意大利苍耳的入侵机理及增加农业产量具有非常重要的参考价值。通过水蒸气蒸馏法提取意大利苍耳叶、茎、果三个部位的挥发油，并通过GC-MS对其化学成分进行分析鉴定。在叶、茎、果挥发油中分别鉴定出25、23、27种化合物，分别占总成分的90.625%、93.041%、89.866%。以意大利苍耳入侵生境中常见杂草反枝苋(Amaranthus retroflexus L.，双子叶植物)和早熟禾(Poa pratensis L.，单子叶植物)作为受试植物，在密闭容器中(容积为1.4 L)放入不同质量的叶、茎、果(20 g、40 g、80 g)，模拟其在自然状态下产生的挥发物的化感作用；并采用培养皿法对不同浓度叶、茎、果挥发油(0.2 μl/ml、0.5 μl/ml、1 μl/ml、3 μl/ml、5 μl/ml)的化感作用进行生测。结果显示：意大利苍耳各部位在自然挥发条件下以及其挥发油均表现出较强的化感作用，其叶挥发油在5 μl/ml时可完全抑制两种受试植物种子的萌发，具有进一步开发为植物源除草剂的潜力。研究了意大利苍耳入侵土壤、入侵土壤灭菌处理、入侵土壤加入一定比例的活性炭对受试植物的影响。结果表明：对早熟禾的苗高而言，从大到小依次为灭菌土壤>未灭菌土壤>活性炭处理土壤。对反枝苋而言，灭菌处理之后，根长、苗高、鲜重、干重的值最大，并且其鲜重、干重显著高于未灭菌和加入活性炭处理土壤。整体而言，经过灭菌处理土壤受试植物的根长、苗高、鲜重和干重均是最高的。研究了不同浓度的意大利苍耳水提液(0.025，0.05，0.1 g/ml)对入侵地土壤微生物群落结构、土壤酶活性和土壤养分的影响。结果表明，意大利苍耳水提液处理使土壤中细菌数量显著增加，并在处理浓度为0.05 g/ml时达到最大值 (38.5×106 CFU/g)。整体上真菌数量呈增加的趋势，而意大利苍耳不同浓度水提液处理下放线菌数量均低于对照土壤。Biolog分析结果显示，不同处理下土壤的平均颜色变化率(AWCD)均显著低于对照。对31种碳源进行主成分分析，提取与碳源利用有关的2个主成分，分别能解释变量方差的68.2%和11.3%，糖类、羧酸类、氨基酸类是微生物利用最高的碳源。水提液处理显著增加了土壤速效氮和速效钾的含量，并且增加了土壤脲酶和蔗糖酶的活性。相关性分析表明，土壤脲酶活性与土壤蔗糖酶活性及细菌数量呈正相关，与放线菌数量呈负相关；土壤有机质与土壤脲酶、土壤蔗糖酶和细菌数量呈正相关，速效氮、速效钾与土壤脲酶、土壤蔗糖酶和真菌数量呈正相关。以上研究结果表明，意大利苍耳水提液可以改变土壤微生物群落结构、土壤酶活性和土壤养分，从而使其更加有利于自身的生长和扩张。研究意大利苍耳植株粉末、乙醇提取物、水提取物处理对入侵地土壤微生物群落结构功能多样性、土壤酶活性和土壤养分的影响。结果表明，植物粉末、乙醇提取物和水提取物处理土壤细菌数量均显著高于对照土，植物处理细菌的数量为对照的13倍。三种处理土壤放线菌数量均显著低于对照土壤。Biolog分析结果显示，不同处理的AWCD值均低于对照土，其大小顺序为对照土> 水提取物>植物粉末>乙醇提取物，说明意大利苍耳处理土壤显著降低了土壤微生物的碳源利用率。对31种碳源进行主成分分析，提取与碳源利用有关的2个主成分，分别能解释变量方差的41.6%和27.9%，糖类、羧酸类、氨基酸是微生物利用最高的碳源。植物粉末处理和水提取物处理土壤酶活性均高于对照土。三种不同处理土壤各养分含量均高于对照土。相关性分析表明，细菌数量与土壤酶(除碱性磷酸酶和蛋白酶)活性、真菌数量及各养分含量均呈正相关；脲酶活性与蔗糖酶活性、酸性磷酸酶活性、细菌数量、真菌数量和各养分(除全钾)含量均呈正相关；除过氧化氢酶活性和放线菌数量以外，酸性磷酸酶活性与其余微生物数量、土壤酶活性、各养分含量均呈正相关。
英文摘要	Xanthium italicum Moretti (family Asteraceae, Compositae) is an annual weed native to the Americas. It was first found and reported in 1991 in Beijing, and now has been widely distributed in China. X. italicum harmed the growth of crops such as corn, cotton, soybean, which caused great economic losses to the agricultural production in China. In this paper, the allelopathy of the volatilels of different parts of X. italicum soil microbial functional community structure, soil enzyme activity and soil nutrient content, which were important to further understand the allelopathy of X. italicum and increase agricultural production. The essential oil was obtained from leaf, stem, fruit of X. italicum by steam distillation method, and their chemical composition was identified by GC-MS. In total 25, 23, and 27 compounds were identified from leaf, stemand fruit oils. Amaranthus retroflexus L., a dicot plant, and Poa pratensis L., a monocot plant, which can be found to grow in the habitats that were invaded by X. italicum, were used as tested species to evaluate the allelopathic effects of the plant’s volatile oils. Different amounts (20, 40, 80 g/1.4 L) of fresh cut leaves, stems and fruits of X. italicum were placed in air tight containers to simulate its natural conditions to emit volatile oils into the environment, and petri dish bioassay method was used to evaluate the phytotoxic activity of its essential oils at different concentrations (0.2 μl/ml, 0.5 μl/ml, 1 μl/ml, 3 μl/ml, 5 μl/ml). Our results showed that the volatile oils of different plant parts exhibited significant allelopathic effect both under simulated natural conditions and in the petri dish bioassay. The effects of X. italicum invaded soil, sterilized invaded soil, invaded soil with activated carbon on tested plants were also studied. Overall, root length, seedling height, fresh and dry weights of tested plant species were the highest grown in sterilized soil. The effects of the aqueous extract of X. italicunm (0.025, 0.05, 0.1 g/ml) on the diversity of soil microorganisms, soil enzyme activities and soil nutrients were studied. Our results showed that total bacteria increased significantly when treated with aqueous extract and reached its maximum (38.5×106 CFU/g) when 0.05 g/ml extract was applied. Biolog analysis showed that the value of Average Well Color Development (AWCD) of treated soils was lower than the control. Principal component analysis (PCA) identified two factors in relation to carbon sources; and they explained 68.2% and 11.9% of the variation, respectively. The utilization of sugar, acid and amino acid by microbial community was highest. The aqueous extract significantly increased available N and available K of treated soils as well as the activities of soil urease and invertase. Correlation analysis revealed that soil urease activity and soil invertase activity and soil bacteria were positively correlated, but negatively correlated with actinomycetes. Our results suggested that X. italicum could possibly alter soil microbial community, soil enzyme activities and soil nutrient to create favorable growth conditions for itself. We also compared the potential allelopathic effects of plant powder, aqueous and ethanol extracts of X. italicum on the diversity of soil microorganisms, activities of soil enzymes and soil nutrient. Our results showed that total bacteria increased significantly when soil treated with plant powder, ethanol extract and aqueous extract. Soil actinomycetes under three treatments were significantly lower than the control soil. Biolog analysis showed that the value of AWCD of treated soils was lower than the control. Principal component analysis (PCA) identified two factors in relation to carbon sources; and they explained 41.6% and 27.9% of the variation, respectively. The utilization of sugar, acid and amino acid by microbial community was highest. The soil enzyme activities and all soil nutrients under the treatments of plant powder and aqueous extract were higher than the control soil. Correlation analysis showed that bacteria number was positively correlated with soil enzyme activities (except protease and alkaline phosphatase), the number of fungi and the nutrient content.
语种	中文
学科主题	植物学
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/14980]
专题	新疆生态与地理研究所_研究系统_荒漠环境研究室
作者单位	中科院新疆生态与地理研究所
推荐引用方式 GB/T 7714	邰凤姣. 外来入侵植物意大利苍耳的化感作用[D]. 北京. 中国科学院大学. 2015.

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