Bacterial operational taxonomic units (OTUs) identified in this study.

a

Bacteria were grouped into OTUs defined by 97% sequence identity at the 16S rRNA gene (732–744 bp).

b

Bacteria were grouped into OTUs defined by 99% sequence identity at the 16S rRNA gene (732–744 bp).

c

Based on BLAST analysis (August 2012). Only closest matches to named species are reported.

d

Number of isolates recovered in this study. 24 isolates could only be identified to the family level, including members of the Microbacteriaceae (18), Staphylococcaceae (3), Streptomycetaceae (2) and Pseudomonadaceae (1).

e

Number of plant populations in which the corresponding OTUs were recorded.