Firstly, our results indicated that the primary target traits
should be selected first in the target environments. This was
reflected by the huge differences between ILs generated from
the three selection schemes (Table 1) and by the fact that the
most promising HHZ ILs showing significantly improved DT
and yield in Hainan were originally DT selected (Table 5). This
was not surprising since the initial selection for DT was
carried out in Hainan, whereas the yield performances of the
ST and HY selected HHZ ILs under drought and non-stress
conditions in Hainan were indirect responses. Interestingly,
we observed positive gains of 12.2% and 12.5% in GY under
normal conditions in Hainan as indirect responses to selection
for ST and HY in Beijing, and found no evidence for a yield
penalty associated with DT in the tested HHZ ILs (Table 3).