Fig. 4

Infectivity of Xoo in nine varieties of grass samples within rice fields by cLAMP and PCR, confirming the identification of grass species through grouping and genetic relationship analysis with Xoo infection using a phylogenetic tree. Characteristics of the leaves of nine species of grass samples and the leaves of rice used as the control (O. sativa) after seven days of inoculation (A). Increasing amounts of DNA from grass samples using the cLAMP using LpXoo4009 primer and PCR using Xoo4009 primer by changing the color of the solution inside the test tube of cLAMP and agarose gel electrophoresis of cLAMP and PCR (B). Relationships between Xoo infection and the phylogenetic tree of grasses and rice species of rbcL gene of grass samples (C). The grass species used in this study include Eriochoa procara (G1), Echinochloa crus-galli (G2), Chloris barbata (G3), B. ischaemum (G4), Echinochloa ugandensis (G5), Dinebra chinensis (G6), Cenchrus ciliaris (G7), Digitaria ciliaris (G8), Dactyloctenium aegyptium (G9) and Oryzae sativa (control). For PCR and LAMP assay, water was used instead of DNA template as the negative control (NC). Seven grass species were infected with Xoo (dark blue bars), while the other two non-infected grass species were represented as gray bars. The other grass species were not inoculated by Xoo as indicated by light blue bars. Their sequences were retrieved from GenBank for constructing the phylogenetic tree. The grouping of gels was cropped from different gels and their original images are in Supplementary Information 1.