Plant Disease (2021) 105, 1065-1071

Liangsheng Xu, Yibo Wang, Shan Zhu, Jianyu Li, Yali Chang and Lili Huang (2021)
Development and application of a LAMP assay for the detection of the latent apple tree pathogen Valsa mali
Plant Disease 105 (4), 1065-1071
Abstract: Valsa mali, the causal agent of apple Valsa canker, produces cankers, resulting in the death of infected tissues and eventually the entire tree. Because of the long latent period of the disease, it is necessary to develop a rapid, sensitive, and reliable field-based assay to effectively diagnose apple Valsa canker when the plant is still symptomless. Loop-mediated isothermal amplification (LAMP) is a novel detection method that synthesizes a large amount of DNA and produces the visible byproduct (magnesium pyrophosphate) without conventional thermal cycling. Six LAMP primers were designed to target a species-specific region of the elongation factor-1α sequence, which can be completed at 61°C in 60 min. A positive result is indicated by color change after the intercalating dye SYBR Green I is added. The specificity of the LAMP was validated with DNA from 45 representative isolates of V. mali and closely related species V. malicola, V. leucostoma, and V. sordida. The sensitivity of the LAMP was determined to be 1 ng of DNA or as few as 10 spores. Because the assay does not require expensive equipment or specialized techniques, the LAMP-based diagnostic method can be applied under field conditions to more precisely and efficiently access disease pressure in apple orchards.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
identification/taxonomy

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cytospora mali	Apple (Malus)