Apple replant disease: unraveling the fungal enigma hidden in the rhizosphere

Author: mycolabadmin
11/27/2025
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Summary

Apple orchards that are replanted in the same location often develop a disease that stunts growth and can kill young trees. Scientists discovered that harmful fungi, especially Fusarium species, grow excessively in the soil around diseased trees. These harmful fungi appear to be the main culprits behind the disease. The study identified specific fungicides that can control these pathogenic fungi, offering hope for preventing the disease in future plantings.

Background

Apple replant disease (ARD) is a soil-disease syndrome affecting replanted apple orchards in China’s main growing regions. The disease is associated with microbial community imbalances in rhizospheric soil, with fungal pathogens playing a major role in disease development.

Objective

This study investigated the composition, diversity, and function of rhizosphere fungal communities in healthy and diseased apple trees using Illumina high-throughput sequencing. The researchers aimed to identify ARD-related fungal taxa and elucidate relationships between environmental factors and disease occurrence.

Results

Ascomycota was the dominant phylum in diseased rhizosphere soil (DRS), with Fusarium as the predominant genus. Fusarium abundance positively correlated with ARD severity. Fusarium isolates, particularly F. proliferatum, F. oxysporum, and F. solani, demonstrated high pathogenicity. Mortierella was more abundant in healthy rhizosphere soil and negatively correlated with disease.

Conclusion

Deterioration of rhizosphere fungal community structure is a key biological factor driving ARD, with Fusarium identified as a major causative agent in China. The findings provide insights for developing preventive strategies, including the use of flusilazole and bromothalonil fungicides against F. proliferatum.

Published in:Stress Biology,
Study Type:Observational Study,
Source: 10.1007/s44154-025-00258-1, PMID: 41298948