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Effect Of AM Fungi In Karst Natural Soil On Plants Growth And Nutrient Utilization Of Pioneer Plants

Posted on:2021-04-08Degree:MasterType:Thesis
Country:ChinaCandidate:X HanFull Text:PDF
GTID:2370330623984448Subject:Ecology
Abstract/Summary:PDF Full Text Request
Due to the limitation of environmental conditions,karst habitat is fragile,vegetation is vulnerable to damage and difficult to restore,but it still has a strong potential for restoration.In the early stage of karst vegetation succession,grass,Compositae and other plants are dominant species to form herbaceous weed community,and these herbaceous plants show high adaptability to karst habitat.Arbuscular mycorrhiza(AM)fungi,as an important soil functional microorganism,can help host plants obtain water and mineral nutrition by establishing an extended mycelium network,so as to improve the growth and nutrient acquisition of host plants,and thus improve the adaptability of host plants to the environment.However,AM fungi are often faced with the role of other complex microbial communities in the growth of plants in natural habitats,such as competing for root space and photosynthetic products,etc,which is likely to weaken the ability of AM fungi to promote plant growth and nutrient transfer.At present,the effects of AM fungi on plant growth and nutrient accumulation are mostly based on sterilized soil matrix conditions,but the researches on the effects of AM fungi on plant growth and nutrient accumulation under the complex soil microbial conditions in natural soil have not been paid enough attention.Under natural conditions,soil microorganism is an important factor affecting plant development.Whether AM fungi in karst soil can promote the growth of host plants is disturbed by coexisting soil microbial community is still unknown.Therefore,this experiment selects four kinds of karst pioneer herbs as the research object.By setting three kinds of soil treatments,the effects of AM fungi on the growth,nutrient uptake,soil nutrient and enzyme activity of pioneer herbs in karst natural soil are studied,which will further explore the am in Karst fragile habitat It has important theoretical and practical significance in function,microbial adaptive regulation mechanism of plant community succession and application of mycorrhizal biotechnology in karst vegetation restoration.In this experiment,we set up the planting treatment of natural soil inoculated with glomus etunicatum,sterilized soil inoculated with glomus etunicatum and sterilized soil without glomus etunicatum,and Setaria viridis,Arthraxon hispidus,Bidens pilosa and Bidens tripartita were planted respectively.After 20 weeks of planting,the biomass,N,P,K nutrient status,soil nutrient status and soil enzyme activity index of each organ were measured.The main results were as follows:(1)The application of AM fungi can significantly promote and improve the growth and root morphology of S.viridis,A.hispidus,B.pilosa and B.tripartita,but the natural soil reduces the effect of AM fungi on the growth of S.viridis,A.hispidus,B.pilosa and B.tripartita;different species have different responses to AM fungi,AM fungi have the strongest effect on the growth of A.hispidus,B.pilosa and B.tripartita Secondly,the promotion effect of S.viridis is the weakest.(2)The application of AM fungi can significantly promote the uptake of N,P and K in the organs of S.viridis,A.hispidus,B.pilosa and B.tripartita,but natural soil significantly reduces the effect of AM fungi on the nutrient accumulation of S.viridis,A.hispidus,B.pilosa and B.tripartita.The response of different species to AM fungi was different,but the accumulation of N,P,K in S.viridis was significantly lower than that in A.hispidus,B.pilosa and B.tripartita,while the uptake of N,P,K in A.hispidus,B.pilosa and B.tripartita was the highest,followed by A.hispidus,B.pilosa and B.tripartita,but the difference was slightly different.(3)The application of AM fungi significantly reduced the concentrations of TN,AN and AK in A.hispidus,the concentrations of TN,alkali hydrolyzed,TP,AP and AK in B.pilosa,and the concentrations of TN,AP and AK in B.tripartita.Compared with AM fungi alone,the soil TN and alkali hydrolyzed nitrogen,AP and AK of four plants were increased,and the TP was decreased.There was no significant change of soil N and P in different species,but the TP in the soil of S.viridis was significantly higher than that of A.hispidus,B.pilosa and B.tripartita,while the AP was significantly lower than that of A.hispidus,B.pilosa and B.tripartita.(4)Application of AM fungi significantly increased the activities of soil polyphenol oxidase and soil catalase of B.pilosa,and increased the activities of soil alkaline protease of S.viridis,A.hispidus and B.pilosa and soil alkaline phosphatase of A.hispidus.Compared with AM fungi alone,natural soil increased soil catalase of A.hispidus and soil alkaline phosphatase of S.viridis,B.pilosa and B.tripartite,decreased the soil polyphenol oxidase of B.pilosa and B.tripartite,decreased soil catalase of S.viridis,B.pilosa and B.tripartite,decreased the soil alkaline protease of S.viridis,A.hispidus and B.pilosa and soil alkaline phosphatase of A.hispidus.The soil enzyme activities of different species were different.The activity of soil polyphenol oxidase of S.viridis was lower than that in the other three species,and soil alkaline protease of soil alkaline protease was lower than that in the other three species.However,the activities of soil catalase and soil alkaline phosphatase in four plant soils had no significant difference.In conclusion,AM fungal inoculation can significantly promote the biomass accumulation and the uptake of N,P and K of S.viridis,A.hispidus,Bidens pilosa and Bidens tripartite,and reduce the contents of TN and AK of A.,B.pilosa and B.tripartite,promote the activities of polyphenol oxidase and catalase of B.pilosa and B.tripartite,and alkaline protease of S.viridis,A.hispidus and B.pilosa.The effect of AM fungi on the growth and nutrient accumulation of Arthraxon hispidus,Bidens pilosa and Bidens tripartita with higher infection rate was significantly higher than that of Setaria viridis with lower infection rate,but changes of soil nutrients and enzyme activities of different plants were different.However,natural soil significantly reduced the effect of AM fungi on the growth and nutrient accumulation of S.viridis,A.hispidus,B.pilosa and B.tripartita.
Keywords/Search Tags:AM fungi, Pioneer plant, Plant nutrients, Soil nutrients, Soil enzyme activities, Karst
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