Experimental girdling and egg inoculation
Experimental girdling and egg inoculation were performed as previously described with modifications . Briefly, the vascular bundles of E. annuus were cut into two lines using Westcott scissors, and an egg was inoculated between the two girdles. In the non-girdling group, egg inoculation was performed without girdling. The number of flowers was counted 3 weeks after girdling.