The Relieving Effect Of Growth And Physiological Of Erythrophleum Fordii Seedling In Acid-Aluminum Stress With The Application Of Nitric Oxide

This study used the two months potted seedlings of Erythrophleum fordii as experimental material,AICl3 6H2O as the supply of Al3+,and SNP as the supply of NO.The study adopted two-factor completely randomized design as experiment method,vary from the different concentration of SNP(Ommol L-1?0.1 mmol L-1)and Al(Ommol·L-1?0.2mmol·L-1?0.4mmol·L-1?0.6mmol·L-1?0.8mmol*L-1).It setted 10 groups of different treatments,each group had 8 repeatiton.We measured the growth index data(plant height,ground diameter,leaf area,biomass,specific leaf weight,root-shoot ratio,etc.)on a regular basis,and counted and analyzed the growth index and root morphology index(root total average root length,root diameter,root surface area,root number,root volume,etc.)after six months.The study researched the optimum concentration of Aluminum for plant growth,the relief effects of SNP on plant growth and the Aluminum toxicity.It also provided some feasible scientific justification and technical index for the cultivation of Erythrophleum fordii seedlings and the development of urban greening.The main results are as follows:(1)Under the acid-aluminum composite stress,the growth indexes(relative increase in plant height,relative growth of ground diameter,biomass,root to shoot ratio)and the root indexes(total root length,total root volume,total root surface area,root mean diameter,root tip number)of Erythrophleum fordii seedlings were all in the same trend With the increase of concentration of aluminum,the growth indexes and the root indexes of Erythrophleum fordii seedlings shows the tendency of increase first and then decrease.The concentration of A1 is 0.2mM?0.4mM and 0.6mM could promote the growth of Erythrophleum fordii seedlings,and 0.4 mM is the optimum concentration.While the concentration of Al was 0.8mM,the growth indexes and the root indexes of Erythrophleum fordii seedlings showed inhibition phenomenon.So we can see when the aluminum concentration is too large will inhibit the growth of Erythrophleum fordii seedlings.(2)(3)When the aluminum concentration was zero,Compared with the treatments without SNP,the growth indexes and root morphological indexes of Erythrophleum fordii seedlings under the 0.1 mM SNP was more bigger.When the aluminum concentration was 0.8mM,alll indexes of the seedlings were lower than without SNP.In the application of 0.1 mM SNP,the indexes were increased in different degrees.0.1 mM SNP could promote the seedling growth effect of Erythrophleum fordii.the effect was the best when the aluminum concentration was 0.4mM.However,0.8mM Al inhibited the growth of Erythrophleum fordii.NO provided by The SNP solution had obvious effect on alleviating aluminum toxicity.According to the variation trend of the physiological indexes of Erythrophleum fordii leaves in different Al concentration treatments,the chlorophyll content increased with the increase of Al concentration when the Al concentration was changed from 0 to 0.2 mM.At the same time,the content of MDA,proline decreased and the contents of soluble sugar,soluble protein increased,protective enzyme activity changes gently.When the concentration of Al was in the range of 0.2 to 0.8mM,with the increase of the concentration of Al,the chlorophyll content of the Erythrophleum fordii seedlings decreased,the content of MD A increased,the content of soluble sugar and soluble protein decreased,and proline extremely significant increased(P<0.01),and finally to a gentle change.(4)Comepared to the treatment without SNP,When the Al concentration was in the range of 0 to 0.2 mM,the Chlorophyll content of seedling which has been proccessed by 0.1mM SNP rose slightly,the content of MDA decreased slightly.The content of soluble sugar,soluble protein and proline decreased,but the change was little.The activities of protective enzymes increased slightly.When the Al concentration was in the range of 0.2 to 0.8 mM,the chlorophyll content of the seedlings treated with 0.1 mM SNP was significantly increased compared with those without SNP treatment(P<0.01),and the MDA content was significantly decreased(P<0.01).The content of soluble sugar,soluble protein increased significantly(P<0.01)and proline decreased significantly(P<0.01).The protective enzyme activity increased significantly(P<0.01).