The Effects Of Inoculation With AM Fungi On Lanthunam And Lead Interaction Under Salt Stress

According to statistics,about 20% of the world's agricultural soil was affected by salinization.China was a big country in the world salt and alkali land,with about3.6 times 107 hectares of salinized soil.In recent years,as to speed up the industrialization process and the excessive use of agricultural chemicals,led to the world,including China,a number of arid and semi arid areas and coastal shoal soil effect by salinization and heavy metal pollution.Due to the large number of mining rare earth minerals,the soil in the mining area and surrounding farmland presents the characteristics of heavy metal complex pollution,and that made a new soil environmental problems of REE and heavy metals co-contaminate with soil salination.Coexistence of pollution elements in soil and plant systems existed significant interaction,it could changed the behavior of soil environment,bio-availability and plants toxicity,and that effected the process of plant-microbial remediation under multi-metal contaminated soils.Arbuscular mycorrhizal(Arbuscular mycorrhizal,AM)fungi which has the potential with faciliated the phytoremediation of REE and heavy metal pollution,could improved the plants resistance to abiotic stress.Moreover,it was unclear that the effects of inoculation with AM fungi on rare earth and heavy metal interaction under salt stress.Simulating La-Pb co-contaminated soils salinization at levels(La: 0 and 500mg·kg-1;Pb: 0 and 500 mg·kg-1;Na Cl: 0,1.5,3 g·kg-1),a greenhouse pot experiment was conducted to investigate the effects of AM fungi Funneliformis mosseae on La-Pb interaction aspect of AM colonization,biomass,mineral nutrient absorption,Na+ absorption,C:N:P stoichiometric,ionic equilibrium(K+/Na+,Ca2+/Na+,P/Na+),La and Pb absorption,rhizosphere soil p H and EC of nitraria.The results indicated that :(1)Symbiotic associations were established between F.mosseae and nitraria under salt concentration of 0,1.5,3 g·kg-1.The AM colonization rates ranged from18.42%~22.71%,5.24%~11.82%,2.65%~6.69%.But there was no significantly effects of La-Pb interaction on.mycorrhizal colonization.(2)When the salt concentration was 0 g·kg-1,the La500Pb500 treatment was significantly reduced 58.06% compared with the total dry weight of nitraria of La0Pb500 treatment;the La500Pb500 treatment was significantly increased 29.92%compared with the total dry weight of La0Pb500 treatment after inoculated with AM fungi.When nitraria inoculated with AM fungi,the total dry weight of every treatments significantly increased by 36.29%~217.31% under salt concentration of 0,1.5,3 g·kg-1.When the salt concentration was 1.5,3 g·kg-1,the inoculation of AM fungi did not significantly changed the effect of the La-Pb interaction on the total dry weight of nitraria.(3)When salt concentration was 0 g·kg-1,the La500Pb500 treatment was significantly reduced by15.34% of nitraria shoot in P concentration compared with La0Pb500 treatment;but there was no significant effect in the same treatment of inoculated with AM fungi.When salt concentration was 1.5 g·kg-1,compared with La0Pb500 treatment and La500Pb0 treatment,La500Pb500 treatment was significantly reduced by 18.31% and 19.44% of shoot P concentration;but there was no significant effect in the same treatment of inoculated with AM fungi.When salt concentration was 1.5 g·kg-1,inoculation of AM fungi did not significantly changed the effect of La-Pb interaction on P absorption of nitraria.(4)When salt concentration was 0 g·kg-1,the La500Pb500 treatment was significantly increased nitraria shoot of C:N and C:P compared with La0Pb500treatment;When concentration was 1.5 g·kg-1,the La500Pb500 treatment was significantly increased nitraria of C:P and N:P compared with La0Pb500 treatmentand La500Pb0 treatment.When salt concentration was 3 g·kg-1,the La500Pb500 treatment was significantly increased nitraria of and N:P compared with La0Pb500 treatment.There was no significantly changed of La-Pb interaction in the same treatment of inoculated with AM fungi.(5)When salt concentration was 0 g·kg-1,exogenous La addition had significantly increased shoot Pb concentration by 64.2% in the single Pb treatment.But there was no significantly effect of exogenous La addition on shoot Pb concentration in the same treatment of inoculated with AM fungi.When salt concentration was 1.5 g·kg-1,there was no significantly effect of exogenous Pb addition in root Pb concentration on single La treatment.But the treatment of inoculated with AM fungi significantly increased root La concentration by 89.2%.When salt concentration was 3 g·kg-1,exogenous Pb addition had significantly increased shoot La concentration by 41.2% in the single La treatment.Exogenous La addition had significantly decreased root Pb concentration by 96.9% in the single Pb treatment.However in Inoculated AM fungi treatment group,exogenous Pb addition had only significantly decreased root Pb concentration by 43.3% in the single Pb treatment.The experiment preliminary demonstrates that AM fungi could significantly changed the effects of La-Pb interaction on the growth and absorption of elements in halophyte under salt stress.The effects also related to soil salinity levels.Inorder to provides the basic data and theoretical basis for the restoration of heavy metal heavy metal contaminate soil salinization.This study contributed to a better understanding the effects and possible mechanism of AM fungi in the role of REE and heavy metal co-contaminate soil salinization in phytoremediation.