The SAR in both cultivars followed a similar pat
tern at two experimental sites. It rose gradually and
then declined after reaching a maximum, yet the peak
values were different (Fig. 1). From 14 to 28 DPA, the
SAR in BY535 was markedly higher than those in
JM20 (P = 0.01), which indicates that the higher
starch accumulation in the cultivar with a high starch
content was mainly owing to the higher SAR during
mid and late grain filling periods.