Effects of dazomet fumigation and biological fertilizer on strawberry soil fungal diversity under replant conditions

Abstract:

[Background] Strawberry is an important horticultural crops in our country and in the world, but mainly cultivated with annual cropping system in the strawberry area so as to cause continuous cropping phenomenon. Soil-borne disease caused by fungal disease is a major problem in strawberry cultivation. [Objective] Strawberry rhizosphere soils were used as material to explore effects of dazomet fumigation and biological fertilizer on strawberry soil fungal diversity under replant conditions, so as to provide theoretical basis for control of strawberry continuous cropping obstacle. [Methods] Replant soils before (A) or after dazomet fumigation (B) were collected, genomic DNA was extracted, and PCR amplification was made to establish libraries, as the same treatments with the soil samples at stage of flowering with dazomet fumigation (C1) or dazomet fumigation and biological fertilizer (C2). In this study, the fungal ITS1 region was sequenced by Illumina high-throughput sequencing technology on Hiseq 2500 platform, and related biological analysis was conducted to explore the changes of soil fungal abundances, diversities and structures. [Results] A total of 723 fungal OTUs were obtained from 4 strawberry rhizosphere soil samples, among them, Ascomycota and Basidiomycota were the dominant fungi. The fungal abundances and diversities of replant soils were decreased with dazomet fumigation, while the fungal abundances were increased and the fungal diversities were decreased with dazomet fumigation and biological fertilizer. At phylum level, the proportion of Basidiomycota was decreased and Ascomycota was increased with dazomet fumigation, while both of them were increased with dazomet fumigation and biological fertilizer. The analysis of dominant fungal community shows that the fungal proportions were decreased in terms of Acremonium, Aspergillus, Funneliformis, Fusarium, Talaromyces, Alternaria and increased in terms of Malassezia, Ophiocordyceps, Pleurotus with dazomet fumigation, while which were decreased in terms of Funneliformis, Fusarium, Mortierella, Lecanicillium, Dactylella and increased in terms of Aspergillus, Penicillium, Talaromyces, Simplicillium. [Conclusion] In conclusion, fungal diversity was decreased, pathogenic fungals were limited and benificial fungals were boosted with dazomet fumigation and biological fertilizer in strawberry cropping soil. Our results indicated a combination of dazomet fumigation and biological fertilizer could more effectively reduce the strawberry disease.