| 摘要: |
| 【目的】探讨兰州百合（Lilium davidii var.unicolor salisb）连作土壤水浸液对自身幼苗生长的障碍因素及其作用机制。【方法】设置蒸馏水（CK）及正茬、连作2年、连作4年兰州百合根际土壤水浸液各50，100，200，300 mg/mL，共13个处理，以兰州百合种球为受试对象，测定不同条件下兰州百合幼苗生长、抗氧化酶活性、渗透调节物质及细胞膜透性的变化，并利用GC MS技术分析各处理土壤中存在的主要自毒物质。【结果】正茬、连作2年及连作4年兰州百合根际土壤水浸液对兰州百合幼苗的生长均存在“低促高抑”现象，且抑制作用随连作年限的延长而增强。随水浸液质量浓度的增加，兰州百合幼苗CAT和SOD活性逐渐升高，POD活性先上升后下降，MDA含量、相对电导率、脯氨酸及可溶性糖含量的变化呈不断上升趋势，当水浸液质量浓度上升至300 mg/mL时，3个处理中各指标的上升或下降程度与对照相比均达显著差异水平（P<0.05）。兰州百合正茬、连作2年及连作4年根际土壤中分别鉴定出9，15和17种化合物，主要包括2,3-丁二醇、1,2,3-三甲苯、邻苯二甲酸二丁酯、对苯二甲酸二辛酯、抗氧剂2246等化合物，其中大部分为自毒物质。【结论】兰州百合正茬、连作2年及连作4年根际土壤水浸液质量浓度达到300 mg/mL时，对其幼苗的生长会产生显著抑制作用。连作土壤中存在的自毒物质可以改变兰州百合植株体内的抗氧化酶活性，破坏细胞膜结构和功能，抑制兰州百合植株的生长，是导致兰州百合连作障碍发生的重要原因之一。 |
| 关键词: 兰州百合 自毒作用 连作障碍 化感物质 抗氧化酶活性 渗透调节物质 细胞膜透性 |
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| 基金项目:国家自然科学基金项目（31560380）；甘肃省高等学校创新能力提升项目（2019A-072）；甘肃农业大学校级自列项目（GSAU-ZL2015-007） |
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| Autotoxicity of water extracts from continuous cropping soil of Lilium davidii var. unicolor salisb |
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HUANG Yufang,ZHANG Enhe,ZHANG Xinhui,et al
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| Abstract: |
| 【Objective】This study aimed at investigating the obstacle factors and mechanism of water extracts of continuous cropping soil of Lilium davidii var.unicolor salisb on its seedling growth.【Method】The soil samples of stubble,continuous cropping for 2 years and continuous cropping for 4 years were treated by extractions.Four concentration levels of water extracts including 50,100,200 and 300 mg/mL and CK (treated by distilled water) were setup to test their effect on early development of lily.At the same time,the changes in growth,antioxidant enzymes,osmotic regulators and cell membrane permeability of seedlings under above treatments were determined and organic compounds were identified by GC-MS.【Result】The soil water extracts of stubble,continuous cropping for 2 years and 4 years showed promoting effects with low concentration and inhibiting effects with high concentration on the seedlings growth of Lilium davidii var.unicolor salisb.With the increase of concentration of water extracts,activities of CAT and SOD of Lilium davidii var.unicolor salisb seedling gradually increased,activity of POD first increased and then decreased,while contents of MDA,relative conductivity,proline and soluble sugar increased.When mass concentration was 300 mg/mL,the indicators in the three treatments were all significantly different from the CK.There were nine,fifteen and seventeen compounds identified from chloroform extracts of soil samples from stubble,continuous cropping for 2 years and continuous cropping for 4 years,respectively.The components included 2,3-butanediol,1,2,3-tritoluene,dibutyl phthalate,dioctyl terephthalate and antioxidant 2246,most of them were allelophathic substance.【Conclusion】The soil water extracts from stubble,continuous cropping for 2 years and continuous cropping for 4 years had significant inhibitory effect on seedlings growth of Lilium davidii var.unicolor salisb at the concentration of 300 mg/mL.The autotoxic substances existing in the continuous cropping soil of Lilium davidii var.unicolor salisb inhibited plants growth by changing antioxidant enzyme activities in plants and damaging structure and function of cell membrane,which would lead to failure of Lilium davidii var.unicolor salisb continuous cropping. |
| Key words: Lilium davidii var.unicolor salisb autotoxicity continuous cropping allele chemicals antioxidant enzyme activities osmotic adjustment substances cell membrane permeability |
