Analysis of the Differences in Rhizosphere Microbial Communities and Pathogen Adaptability in Chili Root Rot Disease Between Continuous Cropping and Rotation Cropping Systems

Author: mycolabadmin
8/1/2025
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Summary

Rotating crops (chili with cotton) instead of continuously planting chili improves soil health by increasing helpful bacteria like Bacillus and reducing harmful fungi like Fusarium that cause root rot disease. Researchers studied how different cropping systems change the mix of microorganisms in soil around plant roots and identified two main disease-causing fungi. This research shows that crop rotation is a natural, chemical-free way to prevent chili disease and maintain productive farmland.

Background

Chili cultivation faces significant challenges from continuous cropping barriers including nutrient imbalance, soil degradation, and increased disease incidence. Chili root rot, primarily caused by Fusarium species, is a major soil-borne disease that severely affects yield and quality. Crop rotation has been shown to enhance soil microbial environments and reduce disease incidence, but its specific effects on rhizosphere microbial communities in chili cultivation remain unclear.

Objective

To systematically analyze and compare the composition and diversity of rhizosphere soil microbial communities under chili continuous cropping and chili-cotton rotation systems using high-throughput sequencing. To identify key beneficial bacteria and pathogenic organisms that differ between the two cropping systems and characterize the biological properties of primary root rot pathogens.

Results

Crop rotation significantly altered bacterial community structure, increasing Firmicutes and Proteobacteria abundance while enriching beneficial genera including RB41, Lactobacillus, and Bacillus. Fusarium solani (MG6) and F. oxysporum (LG2) were identified as primary pathogens with optimal growth at 25°C and pH 6. Rotation treatment reduced relative abundance of pathogenic fungi Alternaria and Fusarium by 6.62% and 5.34% respectively, with distinct differences in carbon and nitrogen source utilization between pathogenic strains.

Conclusion

Crop rotation enhances soil health and reduces chili root rot incidence by optimizing soil microbial community structure, increasing beneficial bacterial proportions, and suppressing pathogenic fungi. This provides a scientific basis for developing microbial-based sustainable soil management strategies in chili cultivation as an alternative to chemical pesticide use.

Published in:Microorganisms,
Study Type:Comparative Observational Study,
Source: 10.3390/microorganisms13081806 (PMID: 40871310)