连作木薯组培苗根系分泌物的鉴定及其化感效应  

Identification and allelopathic effect of root exudates of tissue-culture cassava under continuous cropping

作　　者：韩笑 张静柔 贝丽萍 黄凯 黎亮武 阳太亿 韦茂贵[1,2,3] HAN Xiao;ZHANG Jing-rou;BEI Li-ping;HUANG Kai;LI Liang-wu;YANG Tai-yi;WEI Mao-gui(College of Agriculture,Guangxi University,Nanning 530004,China;Key Laboratory of Crop Cultivation and Physiology,Education De-partment of Guangxi,Nanning 530004,China;Guangxi Key Laboratory of Agro-Environment and Agro-Product Safety,Nanning 530004,China)

机构地区：[1]广西大学农学院,南宁530004 [2]广西高校作物栽培与生理重点实验室,南宁530004 [3]广西农业环境与农产品安全重点实验室,南宁530004

出　　处：《西南农业学报》2023年第8期1653-1661,共9页Southwest China Journal of Agricultural Sciences

基　　金：国家自然科学基金项目(31960389);广西自然科学基金项目(2018JJA130338)。

摘　　要：【目的】鉴定木薯根系分泌物中的主要自毒物质,为系统研究木薯连作障碍机制及其缓解措施提供理论依据。【方法】以广西主栽木薯品种华南205(SC205)为试验材料,利用其组培苗模拟连作栽培,采用气相色谱—质谱联用仪(GC-MS)和生物测定方法检测其根系分泌物中的主要自毒物质,明确其化感效应。【结果】模拟连作1茬和2茬木薯组培苗的株高、地上部和地下部鲜重均显著低于模拟连作0茬木薯组培苗(P<0.05),其综合化感效应均为负值,且连作2茬木薯组培苗对株高、地上部和地下部鲜重的抑制作用大于连作1茬。从连作木薯组培苗根系分泌物中鉴定出78种化学物质,经GC-MS定量检测发现含量较高的为羟基丙酮、乙酸和2,4-二叔丁基苯酚。与连作0茬相比,连作1茬和2茬木薯组培苗根系分泌物中的乙酸含量分别增加32.40%和16.49%,2,4-二叔丁基苯酚含量分别减少52.27%和85.15%;连作1茬木薯组培苗的羟基丙酮含量增加38.11%,连作2茬木薯组培苗的羟基丙酮含量减少29.03%。生长试验结果表明,2,4-二叔丁基苯酚是对木薯组培苗生长抑制作用最强的自毒物质;羟基丙酮对木薯组培苗生长的抑制作用以高浓度(1×10^(-3 )mol/L)处理大于低浓度(1×10^(-5 )mol/L)处理;乙酸低浓度(1×10^(-5) mol/L)处理可抑制木薯组培苗生长,但高浓度(1×10^(-3) mol/L)乙酸对木薯组培苗生长具有一定的促进作用。【结论】连作木薯组培苗根系可分泌至少78种化学物质,其种类和含量均随着组培苗连作茬数的增加而变化,其中的2,4-二叔丁基苯酚和羟基丙酮属于抑制木薯组培苗生长的重要自毒物质,生产上应采取相应措施减少其产生或缓解其在木薯根系中的累积。【Objective】Identification of the autotoxins in root exudates of cassava(Manihot esculenta Crantz) could provide fundamental knowledge for investigating the formation mechanism of the cassava continuous cropping obstacle and its mitigation process.【Method】Cassava cultivar South China 205(SC205) was used as plant materials,which was the most popular cultivated variety in Guangxi.The plant tissue culture method was applied for the simulation of the continuous cropping of cassava.Identification of autotoxins in root exudates of cassava was conducted by using the gas chromatography-mass spectrometry(GC-MS) technology.The allelopathy of these autotoxins was estimated using the bioassays method.【Result】The plant height,the above-ground biomass,and the underground biomass of the tissue-culture cassava under simulated continuous cropping were all significantly lower than the control(P0.05).The synthesis allelopathic indexes of all simulated continuous cropping treatments were all negative,and the inhibition effects of plant height,the above-ground,and the underground biomass of the 2-round continuous cropping treatment were greater than the 1-round treatment.In total,78 chemical substances were identified in root exudates of the cassava tissue culture under simulated continuous cropping and contents of hydroxyacetone,acetic acid,and 2,4-di-tert-butylphenol were higher than others.Compared to the control,the content of acetic acid of 1-round and 2-round continuous cropping treatments of cassava increased by 32.4% and 16.49%,and the content of 2,4-ditert-butylphenol decreased by 52.27% and 85.15%,respectively.Meanwhile,the content of hydroxyacetone in 1-round treatment increased by 38.11%,whereas that in 2-round treatment decreased by 29.03%.The results of the bioassays methods showed that 2,4-di-tert-butylphenol showed the strongest inhibition to the growth of tissue-cultured cassava seedlings among all tested autotoxins.Hydroxyacetone also inhibited the growth of tissue-cultured cassava seedlings,and the 1×10

关 键 词：木薯 连作障碍 根系分泌物 自毒物质 化感物质 

分 类 号：S533[农业科学—作物学]