Effects Of Different Plant Straws On Tomato Growth And Soil Microbial Community In Continuous Cropping Soil Of Tomato

Tomatoes are one of the main vegetable crops in China,but recent studies have shown that soil-borne diseases severely limit the production of tomatoes due to continuous cropping in years.Among them,root-knot nematodes of tomato are the most serious diseases,even leading to having no harvest.Straw returning can not only improve soil environment,but also improve soil microbial community diversity and prevent disease.The studies have found that,when the straws were added to the soil,microorganism became more active,increasing the resistance of plants and improving the yield and quality of plant,effectively preventing the diseases.But the relationship of different straws,diseases and microorganism remains to be studied.In the experiment,the research object was continuous cropping soil of tomato.Seven kinds of crop straws(maize,wheat,Jerusalem artichoke,marigold,garlic onion and tomato)crushing into pieces were added to in continuous cropping soil of tomato by pot experiment.We explored the effects of seven crop straws on the growth of tomato,the number of galled root,physical and chemical properties of soil and soil enzyme activity and soil microbial community structure.The aims were to explore the effects of the different straw on tomato growth and root-knot nematode diseases and select good straw resources.With the high throughput sequencing method,we explored soil microbial community structure and analyzed straw,diseases and microorganism.So that we lay the foundation for exploring new strategies for preventing soil-borne diseases.The main results of the experiment are as follows:(1)Effects of different straws on the growth of tomato: corn and onion straws promoted the growth of tomato during the whole sampling period;However,the effects of Jerusalem artichoke and marigold straws on the growth of tomato were not obvious or even lower than that of control.(2)Effects of different straws on the number of galled root in tomato: onion straws inhibited the number of galled root during the whole sampling period.(3)The results of abundance and diversity analysis of soil microorganisms showed that compared with control,all the straws significantly decreased the abundance and diversity of soil fungi during the sampling period.All the straws have no significant effect on the abundance and diversity of soil bacteria at 30 th day and 50 th day.And at 70 th day,all the straws significantly decreased the abundance of soil bacteria.(4)The principal axis(PCA)analysis results showed that the Jerusalem artichoke straws,wheat straws,onion straws and tomato straws changed soil fungal community structure at 30 th day and 50 th day.And at 70 th day,the Jerusalem artichoke straws,wheat straws and onion straws changed the soil fungal community structure.The Jerusalem artichoke straws,wheat straws,onion straws and tomato straws changed soil bacterial community structure at 30 th day and 50 th day.And at 70 th day,the Jerusalem artichoke straws and wheat straws changed the soil bacterial community structure.(5)The wheat straws significantly improved the relative abundance of Ascomycota at 30 th day and 50 th day.Jerusalem artichoke straws significantly improved the relative abundance of Zygomycota at 30 th day.The wheat straws increased significantly the relative abundance of the unclassified fungus during the whole sampling period.Jerusalem artichoke straws significantly improved the relative abundance of Mortierella at 30 th day.During the whole sampling period,the wheat straws,Jerusalem artichoke straws and tomato straws significantly decreased the abundance of Sordariomycetes_unclassified.The wheat straw significantly increased the abundance of Proteobacteria during the whole sampling period.(6)Correlation analysis between the number of galled root and microbial taxa showed that the number of galled root in tomato was negatively related with the abundance of Basidiomycota,Firmicutes and Acidobacteria.And the number of galled root was significantly related with the abundance of Chloroflexi and Verrucomicrobia.