Horizontal gene transfer (HGT) in bacteria increases genetic variation and frequently spreads antibiotic resistance throughout bacterial populations. We used biparental mating to study how time impacts recombination rates in P. syringae, an important plant pathogen. After mating single antibiotic resistant mutants (kanamycin or gentamicin) for various times, we quantified colonies resistant to both antibiotics. Only the B728a strain had double resistant colony growth, occurring independent of incubation duration, indicating possible differences in transposon insertion location.