Toxicological Effects Of Nitrobenzene On Leguminous Crops

Based on using nitrobenzene wastewater to irrigate farmlands, and the contamination might doharm to human health and enviroment, we did research on the toxicological effects and pollutantbehavior of nitrobenzene on leguminous crops, using solution culture and pot experiment.Investigated the effects of nitrobenzene on the germination rates, emergence rates, seedling growthand physiological-biochemical characteristics (MDA content, SOD activity, POD activity), soybeanyield and qaulity characters.Using solution culture experiment, discussed the influnce of nitrobenzene to the germinationrates and seedling growth of ten leguminous crops, and results showed that, when the nitrobenzeneconcentration was 1～100mg·L^-1, it had little influnce to germination rates of leguminous crops,with the increasing of nitrobenzene concentration, emergence rates of leguminous crops decreased,but no significance compared with control, and found that the toxicity of nitrobenzene toleguminous related with the concentration, the thresholds of nitrobenzene toxicity to differentleguminous crops were different, under the test conditions, the inhibition of root was larger thanhypocotyl, according to the relationship between the inhition rates of root and hypocotyl length andthe nitrobenzene concentration, the sensitive order of the ten leguminous crops to nitrobenzenewas:small-seedsoybean＞kidneybean＞Dongnong42＞brownbean＞Dongnong49＞Dongnong46＞ormosia＞french bean＞black bean＞mung bean.Using pot experiment, discussed the influence of nitrobenzene to the emergence rates ofsmall-seed bean, ormosia and mung bean, and the influence of nitrobenzene to MDA content, SODactivity, POD activity in root and stem of seedling. The result showed: when the contration waslarger than 5 mg·kg^-1, nitrobenzene delayed emergence of leguminous crops in the initial growingstage, inhibited root growth distinctly, and root of bean abnormally growed, and the number offibre increased under nitrobenzene stress. The influence of root was larger than stem, MDA content,SOD activity, POD activity rose first and then declined with the increasing of nitrobenzeneconcentration in different times, and MDA content, SOD activity, POD activity in stem changedless obviously than in root.Using pot experiment, discussed the influence of nitrobenzene to the yield and qualitycharacters of soybean, the result showed that under the irrigation condition, nitrobenzene obviouslyreduced the number of three and four seeded pods, increased the number of one and two seeded pods to a certain degree, increased the number of shrunken pods, reduced the total number of podsper plant, decreased 100-seed weight and soybean yields. Under the irrigation condition, theinflunence of nitrobenzene to the protein and oil content of soybean seeds rose first and thendeclined, there was no siginifcant difference between treatments and control, but siginificantlyincreased the water content of soybean seed.This paper investigated the toxcological effects of nitrobenzene to leguminous crops for thefirst time, provided scientific foundation for rational utilization of wastewater irrigating fields andthe formulation of field water quality standard for nitrobenzene irrigation, provided strong evidencefor farm products security. This study broke throgh the traditional biology methods as rootelongation, gerimination and seedling growth, took yields and qualities of crops as toxicity indexes,and then could evaluate toxicicological effects of nitrobenzene and pollution behavior scientifictly.