| Based on the current serious water pollution,water shortages and the loss of agricultural production caused by the reduction of pests and weeds that faced by our country.A series of ecological environmental deterioration and agricultural product quality safety problems caused by the abuse of chemical pesticides.There is no idea integrated solutions to solve the effective utilization of biomass resources of sewage hydroponic plants.In view of the above problems,this paper proposes the use of medicinal plants for the restoration of eutrophic water bodies,the adsorption of nitrogen and phosphorus in water bodies as a necessary nutrient for the growth of medicinal plants,and further use of medicinal plant biomass for the extraction of biogenic pesticides.Providing plant materials low toxicity,low residue,and no resistance to bio-sourced pesticides,so as to achieve the purposes of controlling sewage,fixing carbon dioxide,and producing botanical pesticide products,and provide new ideas for the production of bio-sourced pesticides.And provide new ways for the development and utilization of medicinal plant germplasm resources.First,this study selected aromatic medicinal plants with high economic value and vitality(Artemisia annua Linn.,Artemisia vulgaris,Mentha haplocalyx,and Nicotiana tabacum L.)and used eutrophication water to cultivation the four aromatic medicinal plants and the growth of these four aromatic medicinal plants and their effluent purification effects.The experimental results show that the four aromatic medicinal plants can grow normally in heavily eutrophic water,and the plant growth,leaf color and appearance are similar to those of soil culture.The experimental results also show that the water culture medicinal plants can significantly improve the water quality of eutrophic water and their own structure to adapt to changes in the external environment.Therefore,these four aromatic medicinal plants can be used as restoration plants for eutrophic sewage.After 45 days of water culture of the four medicinal plants,the nitrogen and phosphorus contents in the sewage were measured,and the ratio of removing nitrogen and phosphorus was calculated.The result suggests the ability of Nicotiana tabacum L.to remove total nitrogen(TN)was strong,and the removal rate reached 88.68%.The ability of Mentha haplocalyx to remove total phosphorus(TP)was strong and the removal rate reached 75.33%.The four plants have strong absorption ability for nitrogen and phosphorus elements that are necessary for growth.Secondly,Rhizoctonia solani Kühnt,Colletotrichum gloeosporioides Penz,Colletotrichum gloeosporioides Penz,FusaHum graminearum Sehw,Colletotrichum gloeosporioides Penz,Fusarium oxysporum f.sp.vasinfectum(Atk.)Synder & Hansen,Curvularia lunata(Wakker)Boed.and Phytophthora in festans(Mont.)De Bary were used as the test pathogens.The antibacterial activities of different solvent extracts of medicinal plants were studied,and the extraction efficiency of different extraction methods was discussed.The experimental results show that different extraction methods and extraction reagents have different extraction rates for different plants.The extraction efficiency of different solvents is the highest for absolute ethanol extraction,and the two different extraction methods are mainly for higher extraction rate of cable extraction.Artemisia annua Linn.was compared with the same solvent extraction methods on the eight fungi for antimicrobial activity comparison,from the antibacterial activity point of view,the overall difference is not,of which seven kinds of fungi inhibitory effect is almost the same,only FusaHum graminearum Sehw is a heterogeneous strain,Ultrasonic ethanol extraction of Artemisia annua Linn.extracts inhibited FusaHum graminearum Sehw better than that of Soxhlet extraction.One EC50 was 2.0948 g/L and one had no inhibitory effect.During the extraction process,the effective components of FusaHum graminearum Sehw were volatilized.Further analysis of the antibacterial activity of these four medicinal plant extracts on the tested plant pathogenic bacteria found that all extracts had good inhibitory effects on Rhizoctonia solani Kühn and Colletotrichum gloeosporioides Penz.The extracts of Artemisia vulgaris with ethanol and Nicotiana tabacum L.with acetone had EC50 values of 0.3195 g/L and 0.1947 g/L against Rhizoctonia solani Kühni.The extracts of ANicotiana tabacum L.with acetone and Artemisia annua Linn ethanol had EC50 values of 0.56 g/L and 0.7033 g/L against Colletotrichum gloeosporioides Penz.The extracts of Artemisia vulgaris with acetone and Mentha haplocalyx with ethyl acetate had EC50 values of 0.9374 g/L and 0.8003 g/L against Colletotrichum gloeosporioides Penz..All plant pathogens,except for the inhibitory effect onPhytophthora in festans(Mont.)De Baryt,are essentially ineffective,and for the rest of the strains,various extracts also have a good effect on the inhibition of these fungi.The spore germination experiments of Colletotrichum gloeosporioides Penz,Fusarium oxysporum f.sp.vasinfectum(Atk.)Synder & Hansen and Curvularia lunata(Wakker)Boed.of four plant acetone extracts showed that the extracts could effectively inhibit spore germination.Thirdly,the insecticidal activity of different solvent extracts of these four medicinal plants derived from eutrophic sewage hydroponics were studied.The results showed that the acetone extracts of these four medicinal plants(Artemisia annua Linn.,Artemisia vulgaris,Mentha haplocalyx,and Nicotiana tabacum L.)had a certain effect on aphids,and the concentration of the extracts was positively correlated with the death rate of aphids,and the concentration of 24 h(LC)was 0.4211 g/L,0.1782 g /l,0.4015 g/L,0.608 g/L,and virulence regression,respectively.with table 3-23.In addition,the strongest toxicity to aphids is Mentha haplocalyx,and the LC50 in its 12 h is 0.705 g/L.Finally,the antibacterial and insecticidal components of the four medicinal plants extracted from eutrophic sewage were analyzed by GC-MS. |
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