Effects Of Arbuscular Mycorrhizal Fungi(AMF) On Growth And Physiological Characteristics Of Sedum Aizoon L.under Lead Stress

Sedum aizoon L.was perennial succulent plant of the Sedum,and was also a kind of multipurpose plant.It was well known that Sedum aizoon L.was a kind of traditional Chinese medicine in China,and also as a landscaping plant was widely used.In recent years,with the development of industry,soil lead pollution is becoming a more and more serious problem,which had a serious negative impact on plant growth,the growth and development of Sedum aizoon L was also seriously threatened.It has been reported that Arbuscular mycorrhizal fungi?AMF?can form symbiotic relationship with many plants,including Sedum aizoon L.,and promote plant growth,and enhance plant resistance under many stresses.Under lead stress,AMF can enhance the tolerance of symbiotic plant,such as Robinia pseudoacacia L.,Eucalyptus robusta Smith L.,Tagetes eras L.and other plants.However,so far,There was no report on the effect of AMF on the physiological and biochemical characteristics of Sedum aizoon L.under Pb stress.In this study,the effect of arbuscular mycorrhizal fungi glomus Mose?GM?on Sedum aizoon L.growth and physiological characteristics under different lead concentration stress including0mg·kg^-1?250 mg·kg^-1?500 mg·kg^-1?750 mg·kg^-1?1000 mg·kg^-1.The main results are as follows:1.In the absence of AMF,the damage degree of Sedum aizoon L.was different under different lead concentration stress.When the lead concentration was 250mg·kg^-1,the root length and stem diameter are not significantly different from those without lead stress.In addition,under Pb stress,the dry weight of aerial part of Sedum aizoon L.decreased significantly with increasing Pb concentration gradient,but the dry weight of underground part decreased significantly only when the concentration of lead stress was 1000 mg·kg^-1.2.Under Pb stress,the chlorophyll content,chlorophyll fluorescence and other physiological index including the contents of MDA,Pro and Pr and the SOD,POD and SOD activity of Sedum aizoon L.were all significantly changed.The content of chlorophyll and Fv/Fm value decreased significantly and the contents of MDA,Pro,Pr increased gradually with the lead stress concentration gradient.The SOD enzyme activity decreased with the Pb concentrations gradient,while the CAT and POD activity increased first and then decreased.3.In general,AMF significantly facilitated Sedum aizoon L.root length,stem diameter and dry weight controlled with no AMF plants under Pb stress conditions.The plants root length and stem diameter were 23.21cm and 3.69mm,compared with the uninoculated AMF plants and the dry weight was significantly higher.Under lead stress,the inoculation of AMF can significantly increased the chlorophyll content and Fv/Fm value,significantly recovered the decrease of MDA content,enhanced SOD,POD and CAT activity,improved the ability of resistance to Pb stress,induced more Pro and Pr,significantly reduce the lead accumulation in plant underground,alleviated the damage and enhance Sedum aizoon L.resistance under lead stress.