【作者】 高欣欣；

【导师】 申国明；

【作者基本信息】 中国农业科学院 ， 作物栽培学与耕作学， 2012， 硕士

【摘要】 为探明烤烟根系分泌物中的化感物质成分、化感作用及其在土壤中的消解规律，本实验采用砂培法，对中烟100、NC89、K326三个品种中不同组分根系分泌物进行了提取，并结合硅烷化反应，采用GC/MS检测，分离鉴定出烤烟根系分泌物主要物质组成；通过对根系分泌物具体成分的含量和化学特性的分析并结合文献参考，选取主要根系分泌物延胡索酸、肉桂酸、丁二酸、苯甲酸和烟碱进行生物化感测定，具体方法为：通过人为添加控制浓度的方式，研究这些物质对烟草种子发芽率、发芽势和烟苗生长发育的影响。在确定了不同化感物质对烟草生长的化感作用后，通过室内培养法模拟研究了不同温度、水分和不同浓度条件下，烤烟根系分泌物主要成分（延胡索酸、丁二酸、苯甲酸和肉桂酸）在植烟土壤中的消解规律。研究结果如下:(1)3个烤烟品种不同组分根系分泌物主要成分为酸性成分，其中在中性提取条件下，百分含量较高的物质有2-羟基丙酸、肉豆蔻酸、新植二烯、东莨菪素、辛酸等；在酸性提取条件下，百分含量相对较高的物质有3-羟基丁酸、新植二烯、丁二酸、棕榈酸、肉桂酸等；在碱性提取条件下，百分含量较高的物质有新植二烯、棕榈酸、硬脂酸等。2-羟基丙酸、苯甲酸、丁二酸、烟碱、新植二烯、肉豆蔻酸、棕榈酸、延胡索酸等为3个烤烟品种根系分泌物的共有成分。中烟100不同组分根系分泌物对种子发芽率和发芽势的影响程度依次为：中性组分＞酸性组分＞碱性组分。(2)在研究烤烟主要根系分泌物延胡索酸、肉桂酸、丁二酸、苯甲酸和烟碱对烟草种子发芽率、发芽势和烟苗生长发育影响的试验中发现，随着根系分泌物浓度的提高，种子发芽率和发芽势，以及烟草的农艺性状调查数值都出现逐渐减小的趋势。并且不同浓度根系分泌物对种子发芽率、发芽势以及幼苗生长发育的抑制作用存在一致性。结果表明，烟草根系分泌物对烤烟种子萌发和幼苗生长有一定的抑制作用；同时延胡索酸、丁二酸、肉桂酸、苯甲酸和烟碱在不同浓度条件下也能显著抑制烤烟种子萌发和幼苗生长，且抑制作用随浓度的增加而增大，但是五种物质对烤烟种子萌发和幼苗生长的抑制程度不一致，主要表现为：苯甲酸>肉桂酸>丁二酸>延胡索酸>烟碱。(3)延胡索酸、丁二酸、苯甲酸和肉桂酸在土壤中的消解速度较快，各个处理在连续培养7天后基本可以消解完全，温度对各物质消解速度的影响主要变现为，在30℃培养条件下降解速度略快于20℃；在湿度控制方面，土壤湿度为田间最大持水量的60%和80%时，土壤中各种有机酸的消解速度显著快于40%田间最大持水量；各有机酸在土壤中的浓度对其消解速度影响显著，主要表现为随浓度的升高其消解速率逐渐降低，特别是在低浓度时，在土壤培养的前3天内，各个根系分泌物就基本能消解完全，而高浓度的根系分泌物消解速度较慢。更多还原

【Abstract】 In order to study the chemical compositions of root exudates from flue-cured tobacco, theirallelopathy and their dispel rate in tobacco-planting soils, three varieties of tobacco (Zhongyan100,NC89,K326) were used to identify the root exudates in different extracting conditions. The mainmethods of the research are sandy culture, silane treating and GC-MS identification. Through analysingthe content, structure of root exudates from flue-cured tobacco and related articles, benzoic acid、cinnamic acid、fumaric acid、succinic acid and nicotine were used to study their allelopathy on tobaccoseed and tobacco seedlings. After confirming the main allelochemicals’, decomposition speed of essentialcomponent of root exudates（fumaric acid、succinic acid、benzoic acid and cinnamic acid）in plantingtobacco soil was researched by house culture in different temperature、humidness and concentrationsituations.(1) Root exudates in different extracting conditions of the three varieties mainly involve phenols,organic acids and ketones. Under neutral condition, the components of root exudates included2-hydroxyl propionic acid, Tetradecanoic acid, Neophytadiene, Scopoletin and Octanoic acid. Underacid condition, the components of root exudates included3-hydroxy butyrate, Neophytadiene, Succinicacid, Hexadecanoic acid and Cinnamic acid. Under alkaline condition, the components of root exudatesincluded Neophytadiene, Hexadecanoic acid and Stearic acid.2-hydroxyl propionic acid, Benzoic acid,Succinic acid, Nicotine, Neophytadiene, Tetradecanoic acid, Hexadecanoic acid and Fumaric acid wereidentified in the root exudates of all the three varieties of tobacco. The grade of influence by rootexudates of Zhongyan100in different extracting conditions on tobacco seed are (from high to low):neutral condition, alkaline condition and acid condition. Fumaric acid, Succinic acid and Nicotine hascertain inhibition on the germination rate of the tobacco seeds.(2) After a period of time, found that along with the increase of the concentration of the rootexudates（benzoic acid、cinnamic acid、fumaric acid、succinic acid and nicotine）, the tobacco seedlings,seed germination and tobacco plant characters all appear reduce gradually. And the tobacco seedlings,seed germination and tobacco plant characters were had the same inhibitory action among differentconcentrations of root exudates. The result showed that, the root exudates could inhibit the growth oftobacco seedlings, seed germination and tobacco plant characters. Different concentrations of benzoicacid、cinnamic acid、fumaric acid、succinic acid and nicotine could inhibit the growth of tobaccoseedlings, seed germination and tobacco plant characters, and the higher the concentration the bettereffect of the inhibition. But there were great differences in the extent of inhibition between the5rootexudates, benzoic acid>cinnamic acid>succinic acid>fumaric acid>nicotine.(3) Decomposition speed of fumaric acid、succinic acid、benzoic acid and cinnamic acid wasquickly，which could be disappear completely in7days. Temperature had little influence on thedecomposition speed,4kinds of organic acids at20℃decomposed faster than30℃. When the soilmoisture was60%of the maximum moisture capacity, the decomposition speed of4kinds of organicacids faster than40%and80%. Concentration had more influence on the decomposition speed, withincreasing of organic acids in the soil, the decomposition speed of them decreases quickly.更多还原