Figure 3. Procedure of Xoo dilution and growth.

A and B. Take a 6 cm-length leaf fragment next to the inoculated site with pretreated scissors and tweezers. C. Immerse the leaf fragment into 75% ethanol for 1 min for surface sterilization. D. After being dried, cut the leaf fragment and grind the sample to homogenize with 1 ml sterilized water, and take 100 μl homogenate to a new 1.5 ml tube containing 900 μl sterilized water and mix thoroughly. Repeat this step for several times until to tube n with appropriate dilution. Take 100 μl diluted homogenate from each of the diluted tubes and spread on PSA solid media. Incubated at 28 °C for 2-3 days until obvious colonies formed.