Toxicological Effects Of DBP And DEHP On Wheat

The effects of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) on germination, physiological indexes, photosynthesis of wheat seedlings and the accumulation of DBP and DEHP in wheat roots and shoots were studied in this paper.The results were as follows:(1)The effects of DBP and DEHP on the germination of wheat seedsThe germination rate, root elongation and shoot elongation of wheat seeds had eco-toxicity sensibility on DBP and DEHP. Sequence orders was root elongation> shoot elongation> germination rate, in which the control rate of root elongation was better index for evaluating DBP and DEHP eco-toxicity.(2) The effects of DBP and DEHP on photosynthesis of wheat seedlingsThe decrease of Pn in wheat seedlings at low and medium concentrations of DBP and DEHP were due to stomatal limitation, the PS â…¡ reaction center of wheat seedlings protected their photosynthetic machinery through timely dissipation. Whereas the decrease of Pn at the high concentration of DBP and DEHP might be caused by both stomatal and non-stomatal limitation, the heat dissipation effect of wheat seedlings might be lost. Both DBP and DEHP had decreased the growth of wheat roots significantly (P<0.05).(3) The effects of DBP and DEHP on the physiological indexes of wheat seedlingsWith increasing of DBP and DEHP concentrations and incubation time, the membrane system of wheat seedlings might be damaged. The film structure of wheat seedlings might be changed. Furthermore, the damage of wheat roots was more serious than shoots.(4) The accumulation of DBP and DEHP in wheat seedlingsThe accumulation of DBP in wheat seedlings was obviously higher than DEHP (P<0.05). The concentration of DBP/DEHP in wheat roots was higher than that in shoots.(5) The comparison of the toxic effects of DBP and DEHP on wheat seedlingsStudies showed that the toxic effect of DBP on the germination, physiological indexes, photosynthesis of wheat seedlings was significantly greater than that of DEHP (P<0.05), which might be related to their molecular structure.