Rapid and Accurate Detection of Podosphaera leucotricha in Apple Trees by Loop‐Mediated Isothermal Amplification ( LAMP )

ABSTRACT

Apple production faces significant economic losses due to powdery mildew caused by Podosphaera leucotricha . Rapid and accurate detection is essential for disease control. Here, we describe a loop‐mediated isothermal amplification (LAMP) assay for the specific identification of P. leucotricha . Primers were designed based on the internal transcribed spacer (ITS) region of ribosomal DNA. The reaction temperature and time were optimised based on the earliest threshold time (Tt) and highest endpoint fluorescence intensity. The optimal conditions were determined as 64°C for 20 min. The LAMP assay proved highly specific, showing no cross‐reactivity with any of the non‐target fungal species tested. Detection sensitivity reached as low as 10 ⁻²  fg μL ⁻¹ of target DNA. When tested on naturally infected apple leaves from the field, the LAMP assay successfully detected P. leucotricha , with results consistent with conventional PCR analysis. The LAMP assay presented here offers a rapid, reliable and practical solution for on‐site diagnosis of apple powdery mildew.