紫茎泽兰叶片对小麦、油菜幼苗的化感作用及化感机制的初步研究

采用培养皿滤纸法和盆栽法,研究外来入侵种紫茎泽兰(Eupatorium adenophorum)叶浸提液对小麦、油菜2种作物的化感作用及其生理学效应,以初步探讨其化感机制.结果表明:油菜对紫茎泽兰叶浸提液最为敏感,其浸提液浓度越高,油菜种子萌发的受抑程度越严重,幼苗生长发育的受抑作用越明显,化感系数越大,当紫茎泽兰叶粉末∶湿沙为1∶50时,对油菜的抑制作用就非常明显;经紫茎泽兰叶粉末处理后,小麦根系活力显著降低,丙二醛(MDA)含量降低,超氧化物歧化酶(SOD)活性和过氧化物酶(POD)活性显著增强,但叶绿素含量变化不大.分析认为,紫茎泽兰通过化感作用影响周边植物体内一系列正常的生理学过程,从而使其生长发育受到抑制,并导致紫茎泽兰自身表现出明显的竞争优势,成为入侵物种.

Preliminary study on allelopathic effects and mechanism of Eupatorium adenophorum to wheat and rape seedlings

Through a filter-paper disc method and pot-cultivation experiments,the allelopathy and physiological responses of extraction solution of Eupatorium adenophorum leaves to wheat and rape were studied,and the allelopathic mechanism of this plant invader was discussed primarily . The results showed that rape seeds were most hypersensitive to the extraction of E . adenophorum leaves;and the higher concentration was,the higher degree of the repression resulted from the extraction,and the seedlings also were repressed with the higher allelopathic coefficient .When the percentage of extraction of E . adenophorum leaves to sands achieved to1∶ 50,the repressive effect of the extration to rape seedlings was obvious . The root activity of wheat seedlings decreased observably after treated with the extractions of E .adenophorum leaves compared to the control,and the contents of malondial-dehyde (MDA) of treated plants also decreased significantly,however,the activities of superoxide dismutase (SOD) and peroxidase (POD) increased strongly,and the chlorophyll contents of treated wheat were remained before and after the treatment . This research showed that E . adenophorum influenced the normal physiological processes of circumambient plants through allelopathic effect,and repressed the processes of growth and development of these plants and further showed the stronger competition superiority,which make it prevailing in some ecosystems .