Continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk soil microflora

Hongjun Liu,Qirong Shen,Dongsheng Wang,Wu Xiong,Rong Li,Ruifu Zhang,Xinnan Hang

doi:10.1007/s11104-017-3504-6

Abstract

AimsBio-organic fertilizer and different additives are widely applied to suppress soil-borne diseases. However, how different additives alter bulk soil microflora and thereby induce the healthy rhizospheric microflora remains unclear.MethodsA 3-season field experiment containing four fertilization management programs (chemical fertilizer, organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer was conducted in a tomato production agroecosystem with high disease incidence to evaluate the induced efficacy. The bacterial and fungal microflora of bulk and rhizosphere soil influenced by different management programs were performed on the Illumina MiSeq platform. Principal coordinate analysis based on the Bray-Curtis distance metric was performed to compare the similarities and differences of the bacterial and fungal community compositions among all soil samples.ResultsSoil amended with organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer progressively and significantly suppressed tomato diseases in comparison with chemical fertilizer, and bio-organic fertilizer presented the best efficacy in all seasons. Interestingly, rhizospheric and bulk soil bacterial and fungal communities of the different fertilization management programs were separated from each other. Six bacterial and 10 fungal rhizospheric genera positively correlated with the same genera observed in bulk soil showing significant relationships with tomato disease incidence were observed, and functional strain SQR9 can be detected in the bulk and rhizosphere soils of bio-organic fertilizer treatments. Additionally, the redundancy analysis results showed the genera in treated chemical fertilizer bulk soil were dominated by Ralstonia and Fusarium, the abundances of which were highest and lowest in treated chemical fertilizer and bio-organic fertilizer rhizosphere, respectively.ConclusionsThis study provided insights into soil-borne disease suppression by bulk soil management and confirmed that alterations to the bulk soil microbiota by different organic additives played distinct roles in the formation of rhizospheric soil microflora for the suppression of disease.

Highlights

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops cultivated worldwide (Singh and Siddiqui 2015)
Soil amended with organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer progressively and significantly suppressed tomato diseases in comparison with chemical fertilizer, and bio-organic fertilizer presented the best efficacy in all seasons
Six bacterial and 10 fungal rhizospheric genera positively correlated with the same genera observed in bulk soil showing significant relationships with tomato disease incidence were observed, and functional strain SQR9 can be detected in the bulk and rhizosphere soils of bio-organic fertilizer treatments

Summary

Introduction

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops cultivated worldwide (Singh and Siddiqui 2015). It has been reported that plants actively recruit beneficial soil microorganisms in their rhizosphere to counteract pathogen assault (Mendes et al 2011) and that rhizospheric microbial communities are influenced by soil type, plant development, fertilizer management, and other environmental factors (Chaparro et al 2014; Horwath et al 1998). The outcome of these factors is the development of a rhizospheric microbial community that differs markedly from the source communities in bulk soil (Minz et al 2013).

Methods

Results

Conclusion