Rapid and specific detection of Fusarium acuminatum and Fusarium solani associated with root rot on Astragalus membranaceus using loop-mediated isothermal amplification (LAMP)

Root rot, caused by several pathogens, is one of the most devastating diseases on Astragalus membranaceus , and can lead to serious yield loss. Fusarium acuminatum and F. solani are known to be major pathogens causing root rot of A. membranaceus in Shanxi Province, China. It is well-known that accurate identification of the pathogen and early diagnosis of the symptoms play a significantly important role to control this disease in the early or mid-term stage. Here, two new loop-mediated isothermal amplification (LAMP) assays were developed to detect F. acuminatum and F. solani based on the partial translation elongation factor-1α ( TEF-1α ) gene region. The LAMP products were successfully assessed by visual assessment using SYBR Green I, as well as electrophoresis on 2.0% agarose gel. The LAMP reactions for F. acuminatum and F. solani were performed under the optimized conditions of 63 °C and 62 °C for 60 min, respectively. The detection limit of LAMP assay was 100 fg/μL for F. acuminatum and 1 pg/μL for F. solani . Additionally, the two LAMP assays are highly specific to target Fusarium species, and could differentiate F. acuminatum and F. solani from other Fusarium species. In the field, the suspected diseased samples were used to verify the feasibility of the developed assays. As a result, the two rapid and specific LAMP assays could be applied for direct detection of F. acuminatum and F. solani on A. membranaceus , and precise diagnosis of A. membranaceus root rot caused by F. acuminatum and F. solani .