| Popis: |
A preliminary multilocus sequence typing (MLST) analysis of 367 strains within the genus Pseudomonas identified major clades corresponding to P. syringae, P. viridiflava, P. fluorescens, P. putida, P. aeruginosa, and P. stutzeri. Split decompo- sition revealed three primary radiations in the genus, with P. aeruginosa being quite distinct, significant gene flow between P. syringae and P. viridiflava, and moderate gene flow between P. fluorescens and P. putida. Both phylogenetic and population genetic tests indicate that P. aeruginosa has undergone a very recent selective sweep, which purged nearly all of the standing genetic variation in the species, consistent with epidemic population dynamics. P. fluorescens has also undergone a strong selective sweep, although this event appears to be quite ancient. Finally, as reported previously, P. syringae is an endemic pathogen that has maintained a relatively stable population among its plant hosts for a very long time. |
