Effect Of PASP-NAA Coupling On Cadmium Extraction From Biomass Sorghum

Sorghum dochna(Forssk.)Snowden,as a gramineous plant,has the characteristics of high biomass,high tolerance,and certain enrichment ability for heavy metals.It has been increasingly used in the remediation of soil cadmium pollution.However,due to the limitation of self enrichment ability,the remediation effect needs to be strengthened.In this paper,the effects of PASP(polyaspartic acid)and NAA(naphthylacetic acid)on the extraction of cadmium from sorghum were studied by pot experiment with the idea of chelating agent phytohormone coupling regulation to enhance Phytoextraction Technique,The main conclusions are as follows:(1)PASP could significantly promote the growth of biomass sorghum under cadmium stress,and increase the biomass of biomass sorghum.The maximum dry weight of biomass sorghum increased by 12.07%compared with the control;At the same time,PASP can activate cadmium in soil and improve the bioavailability of soil cadmium.Under the action of PASP,the enrichment factor(BF)and transport factor(TF)of biomass sorghum were significantly increased.When the content of cadmium in aboveground and underground parts was the highest,it increased by 67.26%and 22.84%compared with the control.When the cadmium accumulation in whole plant was the highest,it increased by 60.08%compared with the control.The effect of cadmium extraction from biomass sorghum was significantly improved.(2)NAA can significantly promote the growth of biomass sorghum under cadmium stress,and increase the biomass of biomass sorghum,especially the underground biomass.The maximum dry weight of plant and root increased by 9.62%and 25.49%compared with the control;NAA can also improve the effect of cadmium extraction from biomass sorghum to a certain extent.The highest cadmium content in the aboveground and underground parts increased by 17.55%and 18.83%,respectively,compared with the control.The highest total accumulation in the whole plant increased by 32.24%compared with the control.(3)Pasp-naa had a certain coupling effect on the growth of biomass sorghum.The biomass of the pasp-naa coupling treatment group was higher than that of the control group and the treatment group respectively.At the mature stage,the plant dry weight of 5 g·L-1 PASP+20 mg·L-1 NAA treatment group reached the highest value compared with the control group,which was 37.8%higher than that of the control group.Pasp-naa showed a certain coupling effect on Cd accumulation ability of biomass sorghum.The results showed that pasp-naa combined application could further improve the Cd accumulation ability of biomass sorghum,and the CD content in shoot and underground increased by 80.63%and 78.74%respectively compared with the control;Under the treatment of 5 g·L-1 PASP-1 20 mg·L-1 NAA,the effect of cadmium extraction from biomass sorghum was the best,and the cadmium accumulation reached 543.5 UG/plant at maturity,which was 156.65%higher than that of the control.Compared with the application of 5 g·L-1 PASP and 20 mg·L-1 NAA alone,it increased by 32.05%and 124.85%,indicating that the effect of pasp-naa coupling on the extraction of cadmium from biomass can be significantly improved.