The
seedlings were then divided into five groups, one of them was irrigated by 0.5
strength Hoagland nutrient solution (CK, control), in N deficiency treatments, the
seedlings were irrigated by 70% (low) or 95% (high) N abandoned solutions as
described above; while in salt treatments, the seedlings were irrigated by 200 (low)
or 400 (high) mM L1 NaCl solutions respectively. The solutions were renewed once
a week, and there were four replications per treatment.