Molecular Pathogens, 2025, Vol.16, No.3, 111-120 http://microbescipublisher.com/index.php/mp 115 microorganisms, and thus forming a "soil self-purification" ecological barrier. For example, in the tomato-wheat rotation system, wheat plants can induce the growth of antagonistic bacteria such as Bacillus subtilis and Pseudomonas fluorescens, enhancing soil disease resistance (Zhou et al., 2023). Studies have shown that the microecological systems established by different non-host plants are significantly different. Some green manure plants such as vetch and sesbania have the ability to fix nitrogen. While increasing soil organic matter and nitrogen, they activate the proliferation of antagonistic actinomycetes and help inhibit the colonization of Fusarium and Ralstonia (Yang et al., 2023). The improvement of microbial diversity and functional gene richness is one of the key mechanisms for the disease prevention effect of the rotation system. 4 Field Control Effect of Crop Rotation on Disease Frequency 4.1 Comparison of the effects of different rotation years The rotation year has a significant impact on the effect of disease control. Studies have shown that although a short rotation of one year can partially reduce disease pressure, pathogens can still survive in the soil and recur quickly. The implementation of a rotation system of more than two years can more effectively interrupt the life cycle of pathogens and significantly reduce the frequency of soil-borne diseases (Ayana and Fininsa, 2023). In a field trial in Ethiopia, tomatoes were rotated with maize-leguminous composite crops for two seasons. Compared with a single-season maize rotation, the soil content of the pathogen Ralstonia solanacearum decreased by more than 30%, and the incidence of tomato bacterial wilt was significantly reduced (Ayana and Fininsa, 2023). Feng et al. (2023) conducted a two-season rotation experiment of tomatoes and arrow-leaf lotus roots (non-host aquatic plants) in China's greenhouse cultivation system and found that the disease incidence rate decreased by more than 40%, and compared with the single-season rotation, the soil microbial diversity, enzyme activity and organic matter content were significantly improved. The study pointed out that crop rotation is not only a means of biological control of diseases, but also a key path to restore the function of soil ecosystems (Feng et al., 2023). In addition, continuous rotation for many years can suppress the pathogenic microbial population that originally dominated the soil, and antagonistic microorganisms such as actinomycetes and Pseudomonas fluorescens gradually form dominant populations, thereby constructing a "low-risk" soil microecological environment (Lyu et al., 2020). 4.2 Typical non-host plant combinations and disease prevention effects 4.2.1 Rotation with gramineous crops Gramineous crops such as corn, wheat, and millet are common non-host species, and their rhizosphere does not support the reproduction of solanaceous pathogens such as Fusarium and Ralstonia. In a study on tomato-wheat rotation, it was found that two consecutive seasons of wheat cultivation could reduce the Fusarium concentration in the soil by more than 60%, and the disease index was significantly reduced (De Corato et al., 2020). Zhou et al. (2023) also pointed out that wheat as a rotation crop helps activate disease-resistant bacteria in the soil, especially Bacillus and Streptomyces, which release antibiotics and induce plant systemic resistance, thereby improving the health of the next round of Solanaceae crops. 4.2.2 Rotation with legumes Leguminous plants such as soybeans, peas, and vetch are not only non-host plants, but also have nitrogen fixation functions, which can increase soil nitrogen content and improve the microecological environment. In field trials in tropical regions, rotating peppers with peas for one year reduced the incidence of bacterial wilt by 42%, while increasing pepper yield by 18% (Hong et al., 2023). The rhizosphere of leguminous plants is rich in flavonoid secretions, which can promote the proliferation of biocontrol bacteria such as Pseudomonas fluorescens and enhance the pathogen antagonism of soil microecology (Ali et al., 2022). Studies have also found that leguminous plant rotation helps to increase the activity of soil urease and sucrase, thereby improving the nutritional conditions and stress resistance of the root zone (Lin et al., 2022).
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