Fig. 1.

Serial passaging of the phyllosphere microbiome. (A) Experimental design of serial passaging experiment in which microbial inoculum from an agricultural tomato field was inoculated onto replicates of 5 genotypes and passaged for 4 passages. (B) Plants were first inoculated when they were ∼2.5 wk old, and the entire plant was sampled at ∼9 wk old. (C) Bacterial abundance was measured at the end of each passage from experimental (Exp.) and control plants by using ddPCR and normalized to the weight of each plant. Inoculum density was calculated as well. Note that our measures of bacterial growth likely overestimate the starting densities and do not account for population turnover (as a result of cell death and replacement within a passage) and are therefore highly conservative.