Study On The Physiological And Biochemical Resistance To Acute Injury Of Crops Fumigated With HF

Fluoride is a common air contaminant. Its toxicity is 20-100 times than SO2 .In fields near polluting resources of fluorides; normal plant growth was inhibited and grain yield was lowered. So ihat economic loss is serious in agriculture.In this paper fourteen important crops were studied. The study focused on the injury reaction, The sensitive crop horsebean and the resistant crop mung bean were chosen. The study include in the antioxidative enzymes, chlorophyll and protein of pollutant HF at different leaf age and different dose. The results were listed as the following:1 The chlorophyll content and the cell leakage are the denotation of the physiological injury degree of the crops leaves. The area of harmed leaves and the time of the symptoms can show the apparent injury extent of the crops. These four factors related with the resistance of HF. The results showed that it is negative correlation with the cell leakage and the area of the harmed leaves and is positive correlation with the time of the injury symptoms and the content of chlorophyll.2 The activity of antioxidative enzymes in seedling period is improved with the leaves ages, which is old leaves > strong leaves > young leaves.3 The SOD activity of the horsebean and mung bean as enhanced and then inhibited in the period of seedling fumigated with the same concentration of HF. In the anthesis period, the SOD activity of the horsebean was always lower than the control; The SOD activity of the mung bean was higher in the first day, then went or came down. It was obvious that the degree of inhibition of the SOD activity of was higher in the anthesis than the seedling.The SOD activity of horsebean was enhanced and then inhibited fumigated with low concentration of HF and that of mung bean was always higher than the control. The SOD activity of two crops was enhanced then inhibited when exposed to higher(80 μ g/m3) concentration of HF. In the earlier stage of fumigation, the SOD activity of the two crops was increased which was the increase phenomenon caused by the HF pollution. When the dosage added up to some degree, the SOD activity was inhibited in the both crops and the degree of inhibition was greater in the horsebean than in the mung bean.4 The POD activity of the horsebean and mung bean had a slow raise treated with the same concentration of HF in the period of seedling. And the POD activity weaken in the anthesis. This indicated that the antioxidative enzymes were more susceptible to fluoride in the anthesis than that in the seedlings.The POD activity of the horsebean and mung bean,was lentitude raised fumigated with low concentrations of HF. The POD activity increased treated with high concentration of HF. Compared with low HF concentration, the POD activity of both plants had a higher increased ratio treated with high HF concentration. This showed the antioxidative physiological needs of plants under heavy pollution.5 The CAT activity of Both in the seedling and anthesis,had no significant difference with the control...