Growth Response Of Cucumber To Soil Microbial Communities From Conventional Monocropping And Rotation Systems

Greenhouse vegetables with large yield, high efficiency, and annual production will be extensive development, Because of the planting restrictions habits,driven by economic interests, continuous monocropping model of cucumber is increasing, which severely prevent the development of vegetable manufacture.Soil microorganisms is considered to be the main factor for the barrier.Previous studies found that the soil microorganism structure and quantity from the continuous monocropping and rotation cropping systerms were changed, and crop rotation to improve crop yields. It is unclear how the diffirent microorganisms of the monocropping and rotation systems response to the cucumber growth.For this reason, this study on the basis of the existing research on the study of soil microorganisms of continuous cropping and rotation feedback effect on the growth of cucumber, We researched the effect of soil microorganisms of continuous cropping and rotation systems on the cucumber root zone soil bacteria, fungi flora distribution using Miseq sequencing technology, analyzed the effect of soil microorganisms of continuous cropping and rotation systems on cucumber root zone soil of functional groups of microorganisms bacteria, fungi,Pseudomonas, Bacillus communities size using qPCR technology.To investigate the role of changing microbial flora effect on cucumber seedlings grown.The main results are as follows:(1) Compared to continuous cropping, the bacteria of roation treatment increased the abundance of Acidobacteria、Bacteroidetes、Chloroflexi、Acidobacteria、Deltaproteobacteria、Sphingobacteria、Sphingobacteriales、Myxococcales、Pseudomonadales、Pseudomonadaceae、Pseudomonas,decreased the abundance of Actinobacteria 、Actinobacteria、Gammaproteobacteria、Alphaproteobacteria、Clostridia、Gemmatimonadetes、Clostridiaceae、Streptomyces。The fungi of roation treatment decreased the abundance of Ascomycota、Dothideomycetes、Capnodiales、Sordariomycetes 、Hypocreales、Sordariales,increased Pezizomycetes、Pezizales、Eurotiomycetes、Agaricales、Bolbitiaceae。(2) Soil sterilization test results show that the percentage difference of the whole plant, aboveground, underground, total leaf area and total chlorophyll content of rotation and monocropping system were greater than sterilization treatments. Illustrating the difference of cucumber seedlings growth caused by soil of continuous cropping and rotation systems was due to different soil microorganisms.(3) Plant-soil feedback results showed that inoculated rotation treatment of whole plant cucumbers, aboveground, underground fresh and dry weight, soil dehydrogenase, invertase, neutral phosphatase, urease activity are higher than inoculated and sterilization continuous cropping treatment in 10 d, The continuous cropping and rotation microbial treatment increased the fresh weigh,dry weigh soil dehydrogenase, invertase, neutral phosphatase, urease activity. Overall, microorganism population from both cropping systems had a positive effect on the growth of cucumber seeding,and positive effects of rotation microbes are stronger than continuous cropping.(4) The qPCR results showed that soil microbial flora of continuous cropping and rotation changes in soil bacteria, fungi, Pseudomonas and Bacillus quantity. Inoculated with continuous cropping and crop rotation treatments increased the number of soil bacteria, fungi, Pseudomonas and Bacillus, in each period of treatment, compared with inoculated continuous cropping soil and sterilization roation soil treatment, The number of Pseudomonas of rotation treatment were higher,but the fungal quantity is less than inoculated continuous cropping soil treatment. The continuous cropping and rotation microbial treatment increased the size of soil microorganisms,and the effects of rotation microbes are stronger than continuous cropping.(5) Miseq sequencing results showed: continuous cropping and rotation soil microorganisms affected cucumber root zone soil bacterial and fungal community structure. The roation treatment increased the abundance of Actinobacteria 、 Chloroflexi 、 Proteobacteria 、 Actinobacteria 、Alphaproteobacteria、Rhizobiales、Sphingomonadales、Pseudomonadales、Sphingomonadaceae、Pseudomonadaceae 、 Sphingomonas 、 Pseudomonas 、 Streptomyces, decreased the abundance of Bacteroidetes 、 Gemmatimonadetes 、 Sphingobacteria 、 Gemmatimonadetes 、 Sphingobacteriales 、Deltaproteobacteria 、Dothideomycetes、Eurotiomycetes.(6) Adding fungicide and inoculation with AMF and pathogenic tests showed that soil fungicides and bactericides treatments reduced the whole plant, ground and underground fresh and dry weight of cucumber seedlings in rotation soil. But have no effect in continuous cropping soil. Suggesting that rotation eliminate soil fungal communities and eliminate bacterial community both inhibit the growth of cucumber, and elimination of soil fungal communities and eliminate bacterial community of continuous cropping had no effect on the growth of cucumber.(7) AMF inoculation and saprophytes tests showed that the AMF and pathogenic of continuous cropping soil treatment reduced ground and underground fresh and dry weight of cucumber seedlings, AMF and pathogenic of rotation soil the whole plant fresh weight,underground fresh weight, underground dry weight of cucumber seedlings. The percentage difference of the whole plant, aboveground, underground of the AMF of continuous cropping and sterilization treatment were greater than the rotation treatment. The percentage difference of the whole plant, aboveground, underground of the pathogenic of continuous cropping and sterilization treatment were greater than the rotation treatment. Suggesting that the AMF and pathogenic from both cropping systems had a negative feedback on the growth of cucumber seedling, and negetive effects of continuous AMF and pathogenic are stronger than rotation croppingIn summary, the growth early-stage, even as microorganism population from both cropping systems had a positive effect on the growth of cucumber seeding,and positive effects of rotation microbes are stronger than continuous cropping,the growth early-stage, even for rotation and soil microbial flora has no effect on the growth of cucumber. Single soil bacterial and fungal microflora of rotation inhibit the growth of cucumber, The single beneficial and harmful soil microflora growth of cucumber negative feedback effects in continuous cropping and rotation, and the continuous cropping soil microflora are stronger than rotation soil microflora.