Physiological and biochemical characteristics of tebuconazole-resistant isolate of Fusarium oxysporum ZY-W

To determine the physiological and biochemical characteristics of tebuconazole-resistant isolate of Fusarium oxysporum f.sp. fragariae ZY-W,and calculate the resistance risk and mechanism,comparison was conducted between the resistant isolate ZY-W and the sensitive isolate ZY on the activity of phenylalanine ammonia lyase (PAL) and peroxidase (POD),the osmolarity sensitivity,the relative leakage,solution protein contents and electrophoretic patterns of esterases.The result showed that the activity of POD and PAL of ZY-W was higher than that of ZY at all time.The value of PAL treated by fungicide for 0-24 h was increased firstly and then decreased,and reached the peak at 1.5 h. The value of POD in the two isolates was rising all the time,and reached the top at the 24th hour,and the difference between two isolates reached the top at that time.The activity of PAL and POD in both isolates was rising after treated by double distilled water for 0-24 h.Under different conditions,ZY could leak more electrolyte than ZY-W,which means that cell membrane permeability of ZY-W is relatively low.Differences were also found in osmolarity and soluble protein content between two isolates,and the soluble protein content of ZY-W was 0.3 folds higher than that of ZY.In the electrophoretic patterns of esterases,one characteristic band was found in ZY-W.As the result showed,the development of fungicide resistance was accompanied by the changes of the physiology and biochemistry characteristics.