Organic Mulching can Suppress Litchi Downy Blight Through Modification of Soil Microbial Community Structure and Functional Potentials

Background: Organic mulching is an important management practice in agricultural production to improve soil quality, control crop pests and diseases and increase the biodiversity of soil microecosystem. However, the information about soil microbial diversity and composition in litchi plantation response to organic mulching and its attribution to litchi downy blight severity was limited. This study aimed to investigate the effect of organic mulching on litchi downy blight, and evaluate the biodiversity and antimicrobial potential of soil microbial community of litchi plantation soils under organic mulching. Results: Organic mulching could decrease the disease incidence in the litchi plantation. As a result of high-throughput 16S rRNA and ITS rDNA gene illumine sequencing, higher bacterial and fungal community diversity indexes were found in organic mulching soils, the relative abundance of norank f norank o Vicinamibacterales, norank f Vicinamibacteraceae, norank f Xanthobacteraceae, Unclassified c sordariomycetes, Aspergillus and Thermomyces were significant more than that in control soils. Isolation and analysis of antagonistic microorganism showed that 29 antagonistic bacteria strains and 37 antagonistic fungi strains were unique for mulching soils.Conclusions: Thus, we believe that organic mulching has a positive regulatory effect on the litchi downy blight and the soil microbial communities, and so, is more suitable for litchi plantation.