摘要
实验选用紫花苜蓿体内的4种化感物质包括阿魏酸、香豆素、香草酸、香豆酸,以10-3、10-4、10-5mol·L-1和10-6mol·L-1四个浓度,采用培养皿试纸法和沙培法进行苜蓿种子萌发及幼苗生长试验,研究了苜蓿种子萌发和幼苗生长以及抗氧化保护性酶活性的变化,并就生物量、种子萌发和酶活性等三大指标的敏感性进行了讨论。结果表明,4种化感物质对苜蓿种子萌发及幼苗生长有明显的影响作用,这种影响效应与化感物质的种类及浓度显著相关。其中,10-3mol·L-1的4种化感物质均表现出对苜蓿种子萌发有显著的抑制作用,阿魏酸、香豆素和香草酸达到了极显著的抑制效果。当浓度为10-3mol·L-1时,除香豆酸外,其它3种化感物质均表现出对幼苗体内超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸酶(APX)活性有显著的抑制作用,同时使幼苗体内丙二醛(MDA)的含量显著增加;随着浓度的降低,化感物质抑制作用减弱;当浓度降低为10-6mol·L-1时,阿魏酸、香豆素、香草酸则表现出了对上述各种酶活性的轻微促进作用。阿魏酸表现出的化感效应最强,香豆素、香草酸次之,香豆酸最弱。发芽指标受化感物质的影响最敏感、其次是生物量指标,而酶活性指标相对较弱。
The perennial alfalfa(Medicago sativa)is presently used as a forage crop or cover plant to reduce soil erosion caused by wind and water and improve soil quality by nitrogen fixation in many regions of China.But when alfalfa is planted continuously in the same field,its yield will decrease.This is considered to be caused by alfalfa autotoxicity.Allelopathy is one of the important factors which reduce the production of alfalfa.It was reported that some allelochemicals in alfalfa could inhibit seed germination and seedling growth and change root morphology,but the antioxidant enzyme of alfalfa autotoxicity remains largely unknown.According to previous studies,extracts of alfalfa roots,fresh leaves,and litter include phenolics such as vanillic and ferulic acid,p-hydroxybenzoic,o-coumaric,and p-coumaric acid.Ferulic acid,coumarin,vanillic acid and p-coumaric acid were used to test their allelopathic effect on germination,growth and physiological characteristics of alfalfa in this study.The four alleloehemicals were dissolved in distilled water to concentrations of 10^-3 mol·L^-1,from which,solutions of 10^-4,10^-5,10^-6 mol·L^-1 were prepared by adding distilled water.The distilled water was used as control.The objective of our research was to test the alteration of antioxidant defense system by using sand culture method.So as to better understand the allelopathic action mechanism of different allelochemicals.The results showed that the four aUelochemicals had significant allelopathic effects on seed germination,seedling growth and the activity of antioxidant enzyme,and that the physiological activities were significantly related with the concentration of the allelochemical.The seed germination of alfalfa was significantly inhibited under the treatment of 10^-3 mol·L^-1 of the four allelochemicals.Ferulic acid,coumarin and vanillic acid at 10^-3 mol·L^-1 significantly reduced the activities of superoxide dismutase,catalase,peroxidase and ascorbate peroxidase,while the content of MDA in alfalfa seedling was significantly increased.However,ferulic acid,coumarin and vanillic acid could increase the activities of antioxidant enzyme at 10^-6mol·L^-1.In generally,the synthetic allelopathic effects of the four allelochemicals on the growth and antioxidant enzymes activities of seedling ranked,from the strongest to the weakest,in the order of ferulic acid,coumafin,vanillie acid andρ-coumarie acid.
作者
宋亮
潘开文
王进闯
马玉红
SONG Liang;PAN Kai-Wen;WANG Jin-Chuang;MA Yu-Hong(Chengdlu Institute of Biokgy,Chinese Academy of Sciences,Chengdu 610041,China;Graduate School of Chinese Academy of Sciences.Beijing,100039,China;Aba academy of Science and Technology,Wenchuun 623000,China)
出处
《生态学报》
CAS
CSCD
北大核心
2006年第10期3393-3403,共11页
Acta Ecologica Sinica
基金
中国科学院-乐山市院地科技合作资助项目
中国科学院西部之光联合学者资助项目
中国科学院知识创新工程资助项目
国家科技攻关项目子课题资助项目(2005BA807B09LA06
2001BA606A-05-04
2004BA606-05-03)
茂县生态站和瓦屋山生态站资助项目~~
