  The effective quark models are employed to describe the hadronization of QCD
in the quark sector. They reveal a different structure depending on how the
spontaneous chiral symmetry breaking (CSB) is implemented. When the generation
of light pseudoscalar mesons is manifestly incorporated one deals with an
extension of the chiral quark model (CQM) with the non-linear realization of
chiral symmetry. If a model is built at the CSB scale by means of perturbation
theory it generalizes the Nambu-Jona-Lasinio (NJL) one with chiral symmetry
broken due to attractive 4-fermion forces in the scalar channel. The matching
to high-energy QCD is realized at CSB scale by means of Chiral Sum Rules. Two
types of models are compared in their fitting of meson physics. In particular,
if the lowest scalar meson is sufficiently heavy approaching the mass of heavy
\pi'(1300) then QCD favours an effective theory which is dominated by the
simplest CQM. On the contrary, the light scalar quarkonium with a mass of order
500MeV, supports the NJL mechanism.
