Continuous Cropping Duration Alters Green Pepper Root Exudate Composition and Triggers Rhizosphere Feedback Inhibition

作者：Zhou Li, Dongmei Lian, Shaoping Zhang, Yunfa Yao, Bizhen Lin, Jianji Hong, Song‐Hai Wu, Honghong Li · 发表于：Agronomy · 年份：2025 · DOI：10.3390/agronomy15082010 · 被引用次数：3 · 研究领域：Legume Nitrogen Fixing Symbiosis、Plant tissue culture and regeneration、Composting and Vermicomposting Techniques

Continuous cropping poses a significant threat to sustainable pepper production by triggering soil degradation and growth inhibition, yet the role of root exudates in this process remains unclear. This study aimed to elucidate how continuous cropping duration (0, 1, 2, and 6 years) alters root exudate composition and drives rhizosphere feedback in green pepper. Pot experiments revealed that long-term continuous cropping (6 years) severely inhibited pepper growth, reducing photosynthetic rate (32.02%), chlorophyll content (12.26%), plant height (23.89%), and yield (42.37%). Critically, the relative abundance of 3,4-dimethylbenzaldehyde in root exudates increased progressively with cropping duration. Exogenous application of this compound or long-term monoculture extracts reduced soil pH and increased electrical conductivity, altered the rhizosphere microbial community (notably decreasing Proteobacteria abundance and fungal diversity while increasing Bacteroidota and Firmicutes), and significantly inhibited root development and vitality. Correlation analysis indicated that fungal communities were more responsive to soil property changes, while bacterial communities correlated more closely with root traits. This study demonstrates that the accumulation of specific root exudates, particularly 3,4-dimethylbenzaldehyde, is a key driver of continuous cropping obstacles in green pepper by disrupting rhizosphere microbial community structure and soil properties. This highlights the im...