Soil fungistasis and its relations to soil microbial composition and diversity: a case study of a series of soils with different fungistasis

Fungistasis is one of the important approaches to control soil-borne plant pathogens. Some hypotheses about the mechanisms for soil fungistasis had been established, which mainly focused on the soil bacterial community composition, structure, diversity as well as function. In this study, the bacterial community composition and diversity of a series of soils treated by autoclaving, which coming from the same original soil sample and showing gradient fungistasis to the target soil-borne pathogen fungi Fusarium graminearum, was investigated by soil bacterial 16S rDNA-PCR (polymerance chain reaction) Cloning, Restriction fragment length polymorphism (RFLP), and sequencing. The results showed that the soil fungistasis capacity was closely correlated with soil bacterial community composition and diversity, i.e., soil fungistasis declined with the decrease of soil bacterial diversity. Meanwhile, the bacterial community composition and structure were significantly different along the gradient of soil fungistasis tested. α-Proteobacteria, β-proteobacteria, Flexibacter and some uncultured soil bacteria were contributed to soil fungistasis in combination with some other special bacteria (Pseudomonas and Acidobacteria) which were know to be key species in suppression of fungal growth.