Comparison of the tuf barcode mean K2P intra- and inter-group divergences.

K2P genetic distances were calculated within (intra) and between (inter) phytoplasma groups. Minimum and average mean K2P inter-group divergences were calculated for all phytoplasma groups. Intra-group divergences could only be calculated for groups with more than one representative. K2P inter-group distance values greater than K2P intra-group distance values (or average inter−/intra-group divergence ratios >1) indicate that inter- and intra- group divergences do not overlap and suggest the presence of a barcoding gap. d, sequence divergence distance; n/a, not available; n/c, not calculated.