I will construct new families of non-hyperelliptic Lefschetz fibrations by applying the daisy substitutions to the families of words in the mapping class group M_g of the closed orientable surface of genus g, and study the sections of these Lefschetz fibrations. Furthemore, I will show that the total spaces of some of these Lefschetz fibraions are irreducible exotic 4-manifolds, and compute their Seiberg-Witten invariants. This is a joint work with Naoyuki Monden.