【作者】 韩旭；

【导师】 程智慧；

【作者基本信息】 西北农林科技大学 ， 蔬菜学， 2013， 博士

【摘要】 大蒜秸秆是大蒜生产中的副产品，通常被作为废弃物丢弃或者焚烧。有效合理地利用这一自然生物资源对减少环境污染和实现农业的可持续性发展是十分必要的。本试验主要研究了不同腐解条件下大蒜秸秆腐解物的化感作用及大蒜秸秆腐解物对不用受体作物的化感作用，并鉴定了大蒜秸秆腐解物中的化感物质，主要结果如下：1.大蒜秸秆腐解后对土壤理化特性有显著影响，能显著提高土壤pH和EC值。腐解温度为40℃、蒜土比例5︰100或腐解60d获得的大蒜秸秆腐解物能显著增加土壤中全氮和有机碳的含量。低温（10℃）、高浓度（5︰100）或短时间（10或20d）腐解的腐解物使土壤蔗糖酶、脲酶和碱性磷酸酶活性达到最大值。短时间（10d）、低温（10℃）或高浓度（5︰100）腐解的大蒜秸秆对土壤特性表现出最强的化感促进效应。2.以小麦和莴苣为受体作物，研究不同腐解时间的大蒜秸秆腐解物的化感作用。结果表明，短时间（10或20d）腐解的大蒜秸秆腐解物能够显著抑制小麦和莴苣的生长，30或40d腐解则促进受体生长。较长和长时间（30、40、50和60d）腐解显著增加小麦和莴苣的地上部和根系的鲜重，而短时间（10或20d）腐解显著降低其鲜重。腐解30d的大蒜秸秆腐解物显著增加小麦和莴苣叶片中叶绿素和蛋白质含量，并提高超氧化物歧化酶（SOD）和过氧化物酶（POD）活性。不同时间腐解的腐解物均显著提高种植小麦和莴苣的土壤脲酶，蔗糖酶和碱性磷酸酶活性。腐解30d的大蒜秸秆对小麦和莴苣的生长发育及种植二者的土壤特性均表现出最强的化感促进作用。3.不同温度腐解的大蒜秸秆腐解物对受体作物小麦和莴苣有明显的化感作用。高温（40℃）条件下的腐解物显著促进小麦和莴苣根系和地上部的生长，增加其鲜重，但低温（10℃）条件下的腐解物表现显著的抑制作用。40℃腐解的腐解物显著降低小麦和莴苣叶片中丙二醛（MDA）含量，但却提高SOD活性。10℃腐解的腐解物显著提高小麦和莴苣叶片中苯丙氨酸解氨酶（PAL）活性及其土壤EC值和蔗糖酶活性，但40℃腐解的腐解物显著提高种植小麦和莴苣土壤的pH值。高温（40℃）腐解的大蒜秸秆对莴苣和小麦的生长发育表现出化感促进作用，但低温（10℃）腐解的则为化感抑制作用。4.以小麦和莴苣为受体作物，研究大蒜秸秆与土壤不同比例（0︰100，1︰100，3︰100和5︰100）条件下腐解物的化感作用。结果表明，低浓度的大蒜秸秆腐解物显著促进小麦和莴苣的生长，而高浓度却抑制其生长。高浓度（5︰100）的大蒜秸秆腐解物显著促进莴苣的根系生长和鲜重的增加，但对地上部的生长和鲜重表现强抑制作用。低浓度的大蒜秸秆腐解物显著提高小麦和莴苣叶片中叶绿素和蛋白质含量以及抗氧化酶的活性。随着大蒜秸秆浓度的增加，种植小麦和莴苣土壤蔗糖酶、脲酶和碱性磷酸酶的活性不断增加。蒜土比例为3︰100的大蒜秸秆腐解物对小麦和莴苣的生长发育表现最强的化感促进作用，但5︰100的腐解物则对二者产生化感抑制作用。5.大蒜秸秆腐解物对不同受体作物表现不同的化感促进或抑制作用。大蒜秸秆腐解物显著促进大白菜根系和地上部的生长，增加其地上部鲜重和叶片中SOD活性；显著促进番茄叶片叶绿素含量和SOD活性，而显著抑制其根系和地上部的生长及鲜重，并降低叶片中POD和PAL活性；显著促进黄瓜和豇豆的根系和地上部的生长，显著提高二者叶片的SOD活性；显著抑制玉米根系的生长，并降低其叶片SOD和POD活性。大蒜秸秆腐解物对大白菜、黄瓜和豇豆的生长发育表现为化感促进作用，但对番茄和玉米的生长发育则表现为化感抑制作用。6.通过GC-MS方法鉴定出大蒜秸秆在腐解的过程中能够分解或者产生新的化感物质。大蒜秸秆腐解物的石油醚、乙酸乙酯和氯仿提取物中有新的物质咖啡碱、N-叔丁氧羰基-L-缬氨酸和二氟尼酸生成。石油醚和乙酸乙酯提取物对莴苣的生物检测表现出化感促进作用，而氯仿提取物则表现为抑制作用。外源化学标准品的验证结果显示，高浓度的咖啡碱、N-叔丁氧羰基-L-缬氨酸和二氟尼酸生物检测均对莴苣表现出化感抑制作用。这些结果与腐解物原不同组分提取物的作用结果相似，并符合化感作用的一般规律，证明这3种物质为大蒜秸秆腐解物中有效的化感物质。更多还原

【Abstract】 Garlic (Allium sativum L.) stalk is a byproduct of garlic production that is normallythought of as waste but is now considered to be a useful biological resource. It is necessary toutilise this resource efficiently and reasonably to reduce environmental pollution and achievesustainable agricultural development. This paper manily studied allelopathy of garlic stalkdecomposition under various decomposied conditions, and researched the allelopathic effectof garlic stalk decomposition on different tested plants. Allelochemicals of garlic stalkdecomposition were identified and verified in this study. The results of allelopathy of garlicstalk decomposition and identification of allelochemicals are as follows:1. Garlic stalk decomposition could significantly affect the physical and chemicalproperties of the soil. The values of soil pH and electrical conductivity were significantlyincreased by garlic stalk decomposition. In addition, total nitrogen and organic carbonconcentration were significantly increased by decomposing stalks at40°C, with a5:100ratioand for10or60days. The highest activities of sucrase, urease and alkaline phosphatase insoil were detected when stalk decomposition was performed at the lowest temperature (10°C),the highest concentration (5:100), and the shortest duration (10or20d). The favorable effectof garlic stalk decomposition allelopathy was performed at shortest duration (10d), the lowesttemperature (10°C), the highest concentration (5:100).2. The allelopathic effect of decomposed garlic stalk over different durations ofdecomposing (10,20,30,40,50and60d) was investigated in this study using wheat(Tricicum aestivum L.) and lettuce (Lactuca sativa var. crispa L.) as test plants. Garlic stalk inearly stages of decomposition (10and20d) inhibited the growth of wheat and lettuce plants,but promoted plant growth in later stages (30and40d). Longer durations of garlic stalkdecomposition (30,40,50and60d) significantly increased the shoot and root fresh weight ofwheat and lettuce, whereas shorter decomposing durations (10and20d) significantlydecreased the shoot and root fresh weight. Garlic stalk decomposed for30days significantlyincreased the content of chlorophyll and protein, and significantly promoted the activities ofSOD and POD. Garlic stalk at different decomposition durations increased the activities ofurease, sucrase and alkaline phosphatase in the soil in which wheat or lettuce was planted. The greatest favorable allelopathy on the growth and development of wheat and lettuce andthe soil properties with planting them was performed at30d of garlic stalk decomposition.3. The allelopathic effect of decomposed garlic stalk at different temperatures wasinvestigated in this study using wheat and lettuce as the allelopathic test plants. Highertemperature (40℃) of decomposed garlic stalk significantly increased roots and shoots lengthof wheat and lettuce, however, lower temperature (10℃) significantly decreased their growth.Garlic stalk decomposed at40℃significantly inhibited the content of MDA of wheat andlettuce leaves, but promoted the activity of SOD. Nevertheless, garlic stalk decomposed at10℃significantly promoted the activity of PAL of wheat and lettuce leaves. Garlic stalkdecomposed at10℃significantly increased the soil EC value and activity of soil sucrasewith wheat and lettuce planted. The greatest favorable allelopathy on the growth anddevelopment of wheat and lettuce was performed at highest temperature (40℃). But thegreatest inhibitive allelopathy was performed at lowest temperature (10℃).4. The allelopathy of decomposed garlic stalk at different ratios (0:100,1:100,3:100and5:100) was investigated in this study using wheat and lettuce as the allelopathic test plants.Lower concentration of decomposed garlic stalk promoted wheat and lettuce plant growth, buthigher concentration inhibited growth. The highest ratio of stalk to soil (5:100) significantlyincreased the root length and fresh weight of lettuce but decreased the shoot length and freshweight. Lower ratio of stalk to soil significantly increased the content of protein andchlorophyll and the activity of plant enzymes of wheat and lettuce leaves. Increasing theconcentration of decomposed garlic stalk increased the activity of soil sucrase, urease andalkaline phosphatase with wheat and lettuce planted. The greatest favorable allelopathy on thegrowth and development of wheat and lettuce was performed at3:100(ratio of stalk to soil).But the greatest inhibitive allelopathy was performed at5:100(ratio of stalk to soil).5. The promoted or inhibited allelopathy of garlic stalk decomposition on various testedplants. Garlic stalk decomposition significantly increased the length of root and shoot, thefresh weight of shoot, and the activity of SOD of Chinese cabbage. Garlic stalkdecomposition significantly promoted the content of chlorophyll and the activity of SOD oftomato. However, garlic stalk decomposition significantly inhibited the length and freshweight of root and shoot and the activities of POD and PAL of tomato. Garlic stalkdecomposition significantly increased the length of root and shoot and the activity of SOD ofcucumber and cowpea. Garlic stalk decomposition significantly decreased the length of rootand the activities of SOD and POD of maize. The garlic stalk decomposition had favorableallelopathy on Chinese cabbage, cucumber and cowpea, but had inhibitive allelopathy ontomato and maize. 6. Garlic stalk resolved or created new allelochemicals during it decomposing whichwere identified by the method of GC-MS. Caffeine, N-à-(tert-Butoxycarbonyl)-L-Valine anddiflunisal were detected from petroleum ether, ethyl acetate and chloroform extractions ofgarlic stalk decomposition, respectively. The petroleum ether and ethyl acetate extractions hadthe favorable allelopathy on lettuce bioassay, but the chloroform extractions had the inhibitiveallelopathy. The results of bioassays of exogenous chemical reference substance showed thathigher concentration of caffeine, N-à-(tert-Butoxycarbonyl)-L-Valine and diflunisal had theinhibitive allelopathy on lettuce bioassay. The results were the similar as the results ofdifferent organic reagent extractions and the general rule of allelopathy. And the threesubstances were verified the effective allelochemicals of garlic stalk decomposition.更多还原