Potential Interactions Between Huanglongbing and Lasiodiplodia-Associated Branch Dieback in Citrus Orchards: A Review of Co-occurrence and Host Responses

Abstract

Huanglongbing (HLB), also known as citrus greening, is currently one of the most destructive diseases threatening citrus production worldwide, having been reported globally. The disease is associated with the phloem-limited, vector-transmitted bacterium Candidatus Liberibacter asiaticus, and its management is strongly dependent on early and reliable diagnosis. However, symptom development is often slow and nonspecific, frequently overlapping with nutritional disorders and abiotic stress. Recent evidence indicates that pathogen detection is more consistent and can be achieved earlier in root tissues than in leaves, emphasizing the diagnostic value of root sampling for early-stage HLB surveillance. Given the economic relevance of citrus as a global commodity, the capacity to identify infections at incipient stages is essential to reduce disease spread and mitigate severe yield and quality losses. In parallel, citrus branch dieback associated with Lasiodiplodia spp. represents another major constraint in citrus orchards. This disease involves complex pathogen-host interactions that disrupt vascular function, impair phloem transport, and induce phloem necrosis, ultimately leading to branch decline and tree weakening. Several Lasiodiplodia species have been linked to citrus dieback, and field assessments suggest that certain citrus relatives may exhibit partial resistance. Understanding the pathogen biology, host responses, and disease mechanisms at the plant–microbe interface is critical for the development of effective control strategies. Furthermore, recent advances in citrus and fungal genomics have improved our understanding of citrus evolution, pathogen diversity, and potential targets for disease management. This review highlights current knowledge on HLB and Lasiodiplodia-associated dieback, emphasizing diagnostic challenges, vascular dysfunction, and emerging molecular tools that may support integrated management approaches for citrus decline syndromes.

Keywords: HLB; Botryosphaeriaceae; Citrus Decline Syndrome; Co-Infection; Vascular Dysfunction

Citation

Santillán-Mendoza R, Flores-de la Rosa FR, Estrella-Maldonado HJ, Matilde-Hernández C. Potential Interactions Between Huanglongbing and Lasiodiplodia-Associated Branch Dieback in Citrus Orchards: A Review of Co-occurrence and Host Responses. WebLog J Agric Crop Sci. wjacs.2026. f0604. https://doi.org/10.5281/zenodo.20902252