RT-LAMP detection of BPMV in soybean seeds. (A) The functional test of RT-LAMP primer set by LAMP assay. 1: Negative control without DNA template; 2: Empty plasmid; 3: Plasmid harboring BPMV CP. (B) Soybean seeds infected by BPMV and healthy soybean seeds. 1: Sample 1; 2: Sample 2; 3: Healthy soybean seeds. (C) One-step RT-LAMP was tried to detect BPMV in soybean seeds. 1: BPMV sample 1; 2: BPMV sample 2; 3: Healthy soybean seeds. (D) Specificity analysis of the RT-LAMP assay for BPMV in soybean seeds. Amplified products were observed by electrophoresis (upper panel) and visually detected by adding SYBER GREEN I for color changes (lower panel). 1: Healthy soybean seed; 2 and 3: Soybean seeds harboring SMV; 4 and 5: Soybean seeds harboring CMV; 6 and 7: Soybean seeds harboring BPMV (sample 1 and 2). 3 μL of (A), (C) and (D) amplified products were checked on a 1% agarose gel electrophoresis in TBE. M: 2 kb DNA marker.