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4646

Areca palm yellow leaf phytoplasma (AYLP) and Areca palm velarivirus 1 (APV1) are two critical pathogens associated with yellow leaf in areca palm, resulting in devastating damage to areca production. However, evidence of their coinfection remains unclear. Areca palms showing yellow leaf symptoms (suspected to be caused by phytoplasma and velarivirus 1) were surveyed and sampled around Hainan Island of China, and the pathogens were identified and analyzed in the study. The results showed that infectious leaf yellowing symptoms of areca palms primarily occurred in eastern and southern cities and counties of Hainan Island. Molecular identification revealed coinfection of ‘Candidatus Phytoplasma asteris’ (16SrI-B subgroup) and APV1 in individual areca palm samples. Among 520 samples tested by qPCR, AYLP was detected in 23.46% (n = 122), APV1 in 53.46% (n = 278), and a coinfection with both AYLP and APV1 in 10.96% (n = 57). A statistically significant difference in APV1 detection rate was observed between asymptomatic and symptomatic plantations (P < 0.0001), suggesting that APV1 infection likely represents an important risk factor for yellowing development in cultivated areca palm populations. These results confirm the coinfection of AYLP and APV1 on Hainan Island, offering epidemiological evidence for targeted disease management.

Abstract Candidatus Liberibacter asiaticus ( C Las), the causal agent of Huanglongbing, is transmitted by the Asian citrus psyllid ( Diaphorina citri ) in a persistent, propagative manner. Reproducible transmission studies require not only controlled inoculation assays but also standardized propagation of citrus host plants, maintenance of D. citri colonies, and reliable pathogen detection. This study presents a comprehensive set of coordinated protocols that collectively support controlled C Las transmission experimentation. The workflow includes propagation of Citrus macrophylla for colony and assay use; generation and maintenance of C Las‐infected citrus and D. citri colonies; synchronization of D. citri populations to enable C Las acquisition; and a controlled single‐ D. citri transmission assay with defined inoculation access periods, and a Dellaporta‐based nucleic acid extraction method compatible with citrus and psyllid tissues. Quantitative PCR detection is integrated throughout to verify infection status, determine C Las titer, and monitor C Las movement and systemic colonization in citrus over time. By combining standardized plant production, vector infection systems, transmission assays, and molecular diagnostics, these coordinated methods provide a unified framework for testing hypotheses about vector competence, pathogen–vector interactions, microbial co‐infections, host susceptibility, and environmental effects on transmission. Together, the procedures enable consistent and comparable assessment of C Las acquisition, dissemination, and transmission outcomes under controlled laboratory conditions. © 2026 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1 : Controlled laboratory method for assessing Candidatus Liberibacter asiaticus transmission by Diaphorina citri Support Protocol 1 : Generation of Candidatus Liberibacter asiaticus‐infected Citrus macrophylla and Diaphorina citri Basic Protocol 2 : Dellaporta total nucleic acid extraction Basic Protocol 3 : Citrus macrophylla propagation

Persian lime (Citrus latifolia Tan.) is a crop of high economic and social relevance in Mexico due to its nutritional properties, associated health benefits, and particularly the foreign exchange generated through exportation. In recent years, the state of Veracruz has become the leading production region for this species at the national level. However, this crop is susceptible to several vascular diseases that cause significant economic losses in the citrus industry. Among these, Huanglongbing (HLB) is considered the most destructive disease, exerting the greatest impact on Persian lime production. This study involved the collection of Persian lime leaf tissues from different sources: field-grown plants, certified nursery plants, and plants previously sanitized through micrografting and thermotherapy processes. Genomic DNA was extracted from the collected samples. DNA integrity was verified by agarose gel electrophoresis and quantified using a NanoDrop One-C spectrophotometer. Quantitative Real-Time Polymerase PCR (qPCR) was performed using a QuantStudio One thermocycler and SYBR Green Master Mix as the fluorescent detection system. Samples were considered HLB-positive when the cycle threshold (Ct) value was below 35 during the quantification of Candidatus Liberibacter asiaticus. The results support the early, precise, and efficient detection of CLas by qPCR in Persian lime plants, thereby contributing to improved diagnostic and phytosanitary management strategies for this crop.