Fig. 2From: Tissue specificity and differential effects on in vitro plant growth of single bacterial endophytes isolated from the roots, leaves and rhizospheric soil of Echinacea purpureaPrimary root length elongation (mm) of seedlings of tobacco plants 7 days after inoculation with different E. purpurea (Ep) endophytesTSB: tryptic soy broth (negative control), CF: culture filtrate. Bars indicate standard errors between two replicates (n = 15). a, c: seedlings belonging to the > 2 cm class; (b), (d): seedlings belonging to the < 2 cm class. *pvalue < 0.05; and ** pvalue < 0.01; *** pvalue < 0.001.Back to article page