Molecular Pathogens, 2025, Vol.16, No.3, 87-99 http://microbescipublisher.com/index.php/mp 88 In recent years, a lot of research has been conducted at home and abroad on the occurrence and prevention of sweet potato root rot, and some progress has been made. On the one hand, plant pathologists have identified the main pathogenic bacteria that cause sweet potato root rot, and elucidated their morphological and molecular characteristics, providing a basis for disease diagnosis and disease-resistant variety breeding (Paul et al., 2020; Kim et al., 2023). On the other hand, field experiments and laboratory studies have explored the influence of environmental conditions, cultivation methods, soil microecology and other factors on the occurrence of root rot (Imperiali et al., 2017; Gao et al., 2019). In terms of prevention and control, traditional chemical treatments are limited by cost and residue issues. In recent years, more attention has been paid to controlling the spread of root rot through comprehensive measures such as healthy seedlings, crop rotation and fallow, biological antagonists and soil improvement (De Mello et al., 2021). Despite this, the current understanding of sweet potato root rot is still incomplete. For example, the role of complex infection of different pathogens, the long-term impact of continuous planting on rhizosphere microbial communities, and the field applicability of new prevention and control technologies still need to be further studied. To this end, this article intends to summarize the pathogen types and biological characteristics, disease patterns and influencing factors, symptom manifestations and diagnostic techniques of sweet potato root rot, as well as comprehensive prevention and control strategies and typical case experiences based on a review of relevant literature in the past five years, analyze the difficulties faced by current prevention and control, and look forward to the future research direction of integrating green prevention and control technology and multidisciplinary collaboration. It is hoped that this review can provide valuable reference for the scientific prevention and control of sweet potato root rot and disease-resistant breeding. 2 Disease Pathogens and Classification Characteristics 2.1 Identification of main pathogenic fungi Sweet potato root rot is usually caused by a variety of soil-borne fungi, among which Fusarium species are the most common and important (De Mello et al., 2021; Paul et al., 2021). Studies have shown that the pathogens of sweet potato root rot in different regions are mainly combined infections of Fusarium oxysporum f. sp. batatas and Fusarium solani: in a survey in North America, F. solani accounted for about 43% of the strains isolated and F. oxysporum accounted for 39% (Scruggs and Quesada-Ocampo, 2016), and similar proportions were found in Asian cases (Kim et al., 2022). F. oxysporum can cause dry rot and wilting of sweet potato tubers and seedlings, and is the culprit of sweet potato wilt and surface dry rot during storage (Paul et al., 2020); F. solani often invades through root wounds, causing sweet potato root dry rot, and the lesions often show obvious concentric ring patterns (Scruggs and Quesada-Ocampo, 2016). In addition to Fusarium, sweet potato tubers are also susceptible to other fungal infections in the field and during storage, causing similar rot symptoms. For example, sweet potato black rot is caused by Ceratocystis fimbriata, which can form black rot spots on the surface of the tubers (Jiang et al., 2019; Wang et al., 2020); Java black rot caused by Monilochaetes infuscans occurs frequently in tropical regions, with symptoms of dark brown necrosis of the potato skin (De Mello et al., 2021). In recent years, studies have also found some cases of infection of sweet potato tubers by unconventional pathogens: Yang et al. (2021) reported that a fungus commonly used as a Biocontrol fungus, Trichoderma asperellum, caused green mold rot of tubers in sweet potato storage in Guangdong, China, which is a new fungal pathogenic variant. This discovery suggests that the pathogenic bacteria of sweet potato root rot may be more complex and diverse than traditionally recognized, and continuous monitoring and identification work is needed. 2.2 Morphological and molecular biological characteristics of pathogens The pathogens of sweet potato root rot have certain morphological characteristics that facilitate routine laboratory isolation and identification. For example, Fusarium oxysporum forms sparse white fuzzy hyphae on the culture medium, produces a large number of small non-septate spores (elliptical to oval), and sickle-shaped multi-septate macroconidia, with the terminal cells often extending tail-like processes. F. solani colonies are mostly cinnamon
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