FIGURE 5
In Exp. 1, the decreased grain filling rate and duration mostly occurred
in phases I for superior grain (Figure 3, Table 1). As the most
important grain filling period (Phase II, fast-increase period for grain
dry matter) (Figure 3), the duration of grain filling in stress
treatment was decreased (Table 1). Compared with CK, the growth duration
was decreased by 4.7 days in DS
treatment, 4.6 days in HS and 2.2 days in DHS treatment. For inferior
grains, the response of grain filling was observed in the early stage
(Phase I). For Exp. 2, the decreased grain weight
in stress treatments was mainly
because of the low grain filling rate while the growth duration was even
extended for superior grains. During the Phase II, grain filling rate
was decreased by 31.1% in DS treatment, 43.4% in HS treatment and
42.3% in DHS treatment. For inferior grains, the decreased grain weight
in stress treatments also resulted from the lower grain filling rate
compared with CK.