Study on the Effects of Mn Stress on the Physiological Resistance of 3 Kinds of Flower Plants

[Objective]The research aimed to provide scientific basis for applying flower plants in the remediation of Mn-contaminated soil.[Method]In pot experiment,the effects of Mn stress on the physiological resistance of Mirabilis jalapa Linn,Calendula officinalis L.and Tagetes erecta L.were studied.[Result]With the increasing of Mn2+ concentration,the content of chlorophyll in the leaves of 3 kinds of flower plants all showed the trend of first increasing and then decreasing and the contents of both MDA and proline showed the increasing trend.The content of chlorophyll in the leaves of M.jalapa,C.officinalis and T.erecta in the treatment with Mn were decreased by 36.00%,5.29% and 10.50% resp.than that in the treatment without Mn addition.The damaged degree of cell membrane system in 3 kinds of flower plants in order was C.officinalisM.jalapaT.erecta.The change of proline content in C.officinalis was most under Mn stress and the proline content had nearly 25 times of difference under Mn stress between the maximum concentration and the minimum concentration of Mn2+.[Conclusion]The tolerance of C.officinalis to Mn stress was higher than that of M.jalapa and T.erecta.