Effects Of Magnetic Field On Growth And Development Of Maize Seedlings

This article aims to explore the effect of magnetic field biological effect on the growth and development of maize seedlings.Based on the indoor hydroponics experiment,Beiqing 340 was used as the test material,and the external magnetic field was applied artificially to provide different magnetic field intensity*magnetic treatment time.The effects of plant morphology,photosynthetic characteristics,peroxidase and endogenous substances on the growth and development of plant seedlings were studied.The main results are as follows:1.By studying the combination of magnetic field intensity and magnetic treatment time,the change trend of dry weight,total leaf area and root dry weight of plants has a reverse linear relationship with magnetic treatment time.Compared with CK,1 00 mT and 175 mT promoted the growth of the plant on the ground,but only 100 mT was effective significantly.It should be noted that the fresh weight of the root has an entire reversed trend,compared with that of being aboveground.The longer the root has been processed,the heavier it would be.It has the strongest positive effect on the promotion of root when it comes to 250 mT*72 h.2.Net photosynthetic rate(Pn),transpiration rate(E),stomatal conductance(GS)and intercellular carbon dioxide concentration(Ci)of maize seedlings treated by magnetic field were higher than those of control.The magnetic field has a significant influence on the photosynthesis of plants.The treatment time of Maize Seedling Pn and magnetic field showed a reverse change,and the 100 m T was the best with all the time treatments.E,GS and Ci all improved with the increase of the time of magnetic field treatment.The 250 mT has the greatest effect on E and GS,and the maximum value appeared at the treatment of 250 mT*48 h is obtained.175 mT field strength has the greatest effect on Ci,and the maximum value appeared at the treatment of 175 mT*72 h.Chlorophyll fluorescence:The magnetic field significantly reduced the qP(photochemical quenching),ETR(?)and Y,and significantly improved Fv,Fv/Fm,Fv/Fm.Fv/Fo,F,Fm and qN.(?)The effect of 250 mT on Fv Fv/Fm Fv/Fv/Fo F Fm qN is greater than 100 mT.But there was no significant difference in the index changes between 24 h and 48 h.3.Compared with the CK,the magnetic field can increase the activity of POD(Peroxidase)and CAT(Catalase Micrococcus lysodeikticus)enzymes in the maize seedlings and reduce the content of peroxides in the plants.The effect of 1 00 mT field strength is the most significant.The POD activity of 24h maize seedlings treated with 100 mT was the strongest,and 100 mT treated 72 h maize seedlings had the strongest CAT activity.The content of MDA(Malondialdehyde)in maize seedlings treated with magnetic field decreased and the effect of 100 mT was the most significant.The soluble protein in the magnetic treatment of maize seedlings increased first and then decreased.Compared with CK,the increase of magnetic treatment 24 h was not significant,and the magnetic treatment 48 h and 72 h decreased significantly.4.The magnetic field inhibits the exudate of abscisic acid in the plant and is lower than the control,and the content of abscisic acid is higher than that of the control,but there is no significant difference.The magnetic treatment 24 h promoted the synthesis of salicylic acid,the time of magnetic treatment was prolonged,and the content of salicylic acid decreased,which was significantly lower than that of the control.The change trend of jasmonic acid was completely opposite to that of salicylic acid.Only if the magnetic field was treated with 72 h,did the melatonin in the plant become higher than that of the control.Overall,to some extent,the magnetic treatment has the positive effect on the growing of maize seedling.It shows that the magnetic treatment has increased the activity of POD and CAT activity,but reduced the content of MDA and the content of soluble protein.With the time of magnetic treatment increasing,the content of abscisic acid and salicylic acid seemed to rise at the begining but decrease as time goes by.The content of jasmonic acid and melatonin increased first and then decreased,which tends to stimulate the growth of maize seedlings.