| In recent years,domestic and foreign scholars' research on cloves has mainly focused on the prevention of plant diseases and insect pests,and there are few studies on the effects of cloves on plant growth and soil environment.In this study,tomato was used as the test material,the germination method on the petri dish paper and the pot test method were used to study the effect of clove ethanol extract on tomato seed germination and seedling,so as to select the most suitable concentration and study the concentration of this concentration on the physical and chemical properties of soil.At the same time,based on high-throughput technology to study the impact of clove extract on soil microbial community structure,further elaborate the relationship between tomato soil microbial community structure and soil environmental factors,provide a theoretical basis for the application of clove extract as a plant bacteriostatic agent in the field.The main conclusions are as follows:1.The seed germination test results show that the concentration below0.500 mg·mL-1 is conducive to promoting seed germination,and the concentration above 0.500 mg·mL-1 will inhibit the germination of tomato seeds.The germination potential,germination rate and germination index of seeds all showed the phenomenon of low concentration promotion and high concentration inhibition.The results of the pot experiment showed that the concentration of 0.500 mg·mL-1 had a promoting effect on both morphological indicators and biomass of tomato,which was beneficial to the increase of the enzyme activity of the seedlings,reducing the degree of membrane damage,and effectively removing superoxide poisoning.2.The results of clove extract on soil physical and chemical properties and enzyme activity show that the application of clove extract is beneficial to improve the soil environment.After applying clove extract,the content of soil total nitrogen,nitrate nitrogen,total potassium,and available potassium was significantly increased.Before and after treatment,they increased by 8.20%,28.00%,and 10.80% compared with CK,respectively,and the effect was significantly higher than that of chemical treatment;It can also effectively increase the activities of soil catalase,urease and sucrase,increasing by 37.45%,54.79% and 35.42%respectively,which has little effect on the activity of neutral phosphatase.3.2,809,675 high-quality sequences were obtained from 36 soil samples,which belonged to 14 Phyla,43 Classes,89 Orders,190 Families,388 Genera,669 Species,and 1440 OTUs.The dominant fungal phyla include Ascomycota,unclassified fungi,Basidiomycota,and Mortierella.Compared with the blank treatment,the application of clove extract and chemical treatment reduced soil fungal species richness and community diversity.Through ?-diversity analysis,it was found that the type of flora changed between different samples.Different samples have significant differences among the genera of Arachniotus,Madurella,Cladomsporium,unclassified?k?Fungi,unclassified?k?Microascaceae.4.2297246 high-quality sequences were obtained from 36 soil samples,belonging to 34 Phyla,93 Classes,257 Orders,481 Families,975 Genera,5273 OTUs,The dominant bacterial phyla are Proteobacteria,Actinomycetes,Curvularia,and Thick-walled Mycophyta,Acidobacteria,Bacteroides,Bacillus,Phytophthora,Rokubacteria,Deinococcus-Thermus.Compared with the blank treatment,the application of clove extract increased the bacterial species richness and reduced the bacterial community diversity;and chemical treatment reduced the bacterial species richness and community diversity.Through ?-diversity analysis,it was found that the type of flora changed between different samples.And there were significant differences among different samples among the genus nk?f?norank?c?Gemmatimonadetes,Pseudomonas,Bacillus,norank?f?Geminicoccaceae,nk?f?norank?o?norank?c?Gitt-GS-136.5.Through the correlation analysis between soil microorganisms and soil physical and chemical properties,it was found that there is a close relationship between soil physical and chemical properties and microbial community structure and abundance.The influence of various factors on the distribution of fungal genus is in order of ammonium nitrogen,available phosphorus,invertase,available potassium,total nitrogen,urease,water content,organic matter,pH,nitrate nitrogen,catalase,total potassium,medium Sex phosphatase,total phosphorus.The influencing factors of bacteria are different,which are ammonium nitrogen,neutral phosphatase,urease,pH,water content,nitrate nitrogen,organic matter,total nitrogen,total phosphorus,sucrase,catalase,total potassium,fast-acting potassium and effective phosphorus. |
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