  The SU($\nu$) generalized Haldane-Shastry spin chain with $1/r^2$ interaction
is studied with twisted boundary conditions. The exact wavefunctions of Jastrow
type are obtained for every rational value of the twist angle in unit of
$2\pi$. The spectral flow of the ground state is then discussed as a function
of the twist angle. By resorting to the motif picture in the Bethe ansatz
method, we show that the period of the spectral flow is $\nu$, which is
determined by the statistical interaction in exclusion statistics.
