蓝桉叶对黑麦草化感作用及其机理的初步研究

Preliminary Study on Allelopathy of Eucalyptus globulus Leaves on Ryegrass and Its Mechanism

选用多年生黑麦草为受体,采用溶液培养法初步研究了不同质量浓度蓝桉叶水浸提液对黑麦草种子萌发和幼苗生长的化感作用及其生理生化的机制.结果表明:不同质量浓度的蓝桉叶水浸提液对黑麦草种子萌发和幼苗生长均有不同程度的影响,表现为低质量浓度促进、高质量浓度抑制,0.02g/mL时促进作用最明显,0.10g/mL时抑制作用最明显,且0.02g/mL处理对黑麦草种子萌发和幼苗生长比较有利;不同质量浓度的蓝桉叶水浸提液使黑麦草体内的SOD,POD活性先升后降,CAT活性逐渐升高,O2.-和MDA含量逐渐增加,并且在0.02～0.04g/mL下处理效果最好;随着蓝桉叶水浸提液质量浓度的增加,叶绿素含量先升后降,在高质量浓度时,细胞受到一定破坏,影响叶绿素合成和光合作用.从而得出:低质量浓度蓝桉叶化感物质对黑麦草种子萌发和幼苗生长具有一定的促进效应,高质量浓度抑制效果明显,0.02～0.04g/mL为最佳处理模式.

The allelopathy of water extract of Eucalyptus globulus leaves of different concentrations on germination of ryegrass seed and seedling growth was studied through solution culture method by using perennial ryegrass as receptor. The results showed that the water extract of E. globulus leaves of different concentrations imposed influences on ryegrass germination and seedling growth to different extents,which was facilitation effect at low concentration and inhibition effect at high concentration. The facilitation function was most apparent at 0.02 g/mL; the inhibitory action was most apparent at 0.10 g/mL. The treatment under the concentration of 0.02 g/mL was relative favorable for both germination of ryegrass seed and growth of seedling. The water extract E. globulus leaves of different concentrations caused the SOD and POD activity in ryegrass to rise first and then to decline,the CAT activity to rise gradually,and the content of O2 and MDA to increase gradually. The best treatment effect was gained under the concentra tion of 0. 02～0.04 g/mL. With the concentration of water extract of E. globulus leaves increased,the content of chlorophyll dropped after initial rise. Cells were destroyed to some extent in case of high concentration with the influences on chlorophyll synthesis and photosynthesis. The E. globulus leaves of low concentration had certain facilitation effect on germination of ryegrass seed and growth of seedling,while they exhibited obvious inhibitory effect at high concentration. The optimal treatment model was gained at low concentration of 0.02～0.04 g/mL.