Abstract: A pot experiment was installed to study the effects of Alternaria azukiae inoculation on the cell membrane permeability,pigment and MDA contents,and activities of SOD,POD and CAT ofTrifolium repens.The results showed that A.azukiae infection made T.repens leaf tissue increase its cell membrane permeability,electric conductivity,over-oxidation and MDA content,but decrease its pigment content.The electric conductivity and MDA content were positively related with infection time,whereas the pigment content was negatively related with it.Due to the stimulation by A.azukiae,the overoxidation of cell membrane was intensified,which resulted in a large amount of active oxygen accumulated and beyond the defense ability,the active oxygen metabolism system was destroyed,and the balance of protective enzyme system was broken.After 12 days of A.azukiae inoculation,the activities of SOD and CAT decreased by 55.2% and 37.8%,respectively,while the POD activity increased by 1.6 times.

Key words: Nilaparvata lugens, Chaos, Power spectrum figure, Return map, Autocorrelation function, Poincare section, Phase trajectory figure