Effects of Root Exudates on the Growth of Wolfberry (Lycium barbarum) and the Development of Root Rot Diseases

This study investigated the intercropping system of wolfberry with forage species, white clover, ryegrass, and mangold by analyzing root exudates extracted via hydroponic methods and their influences on seed germination, seedling growth, and root rot pathogens. This research demonstrates the root exudate-mediated interspecific mechanisms in wolfberry -forage intercropping systems, providing a theoretical foundation for leveraging allelopathy to optimize sustainable agroecological practices. It finds that wolfberry root exudates significantly promoted seed germination in white clover, mangold, and ryegrass, while inhibiting alfalfa germination. Forage root exudates slightly suppressed wolfberry seed germination but markedly enhanced seedling growth, with alfalfa and white clover showing the strongest promotion. Secondly, the primary pathogens causing wolfberry root rot were identified as Mucor circinelloides, Rhizopus arrhizus, Fusarium solani, and F. oxysporum. mangold root rot was predominantly associated with F. solani, Aspergillus niger, and Penicillium solitum. Thirdly, wolfberry root exudates containing autotoxic compounds significantly promoted the expansion of self-associated Fusarium lesions. Legume exudates (alfalfa, white clover) stimulated lesion expansion in Rhizopus and A. niger but suppressed Fusarium mycelial growth. Lastly, wolfberry intercropped with mangold or ryegrass effectively suppressed soil-borne diseases, while legume intercrops (alfalfa, white clover) potentially reduced disease risks by modulating pathogen community structures through allelopathic interactions.