  Precise nature of MBL transitions in both random and quasiperiodic (QP)
systems remains elusive so far. In particular, whether MBL transitions in QP
and random systems belong to the same universality class or two distinct ones
has not been decisively resolved. Here we investigate MBL transitions in
one-dimensional ($d\!=\!1$) QP systems as well as in random systems by
state-of-the-art real-space renormalization group (RG) calculation. Our
real-space RG shows that MBL transitions in 1D QP systems are characterized by
the critical exponent $\nu\!\approx\!2.4$, which respects the Harris-Luck bound
($\nu\!>\!1/d$) for QP systems. Note that $\nu\!\approx\! 2.4$ for QP systems
also satisfies the Harris-CCFS bound ($\nu\!>\!2/d$) for random systems, which
implies that MBL transitions in 1D QP systems are stable against weak quenched
disorder since randomness is Harris irrelevant at the transition. We shall
briefly discuss experimental means to measure $\nu$ of QP-induced MBL
transitions.
