  We discuss Regge trajectories of dynamical mesons in large-N_c QCD, using the
supergravity background describing N_c D4-branes compactified on a thermal
circle. The flavor degrees of freedom arise from the addition of N_f<<N_c D6
probe branes. Our work provides a string theoretical derivation, via the
gauge/string correspondence, of a phenomenological model describing the meson
as rotating point-like massive particles connected by a flux string. The
massive endpoints induce nonlinearities for the Regge trajectory. For light
quarks the Regge trajectories of mesons are essentially linear. For massive
quarks our trajectories qualitatively capture the nonlinearity detected in
lattice calculations.
