When rice is exposed to low light from the
transplanting to the booting stages, head rice yield as
well as amylose in grains increase while the percentage
of chalky kernels and protein content decline (Table 2).
Previous studies indicated that when low light is
imposed during these stages, the source-sink ratio is
markedly altered. That is, biomass of sink organs (the
numbers of fertile panicles and grains per panicle, and
grain size) is significantly reduced. Meanwhile, the
photosynthetic capacity of source organs (leaves)
recovers to a normal level when full light become
available during the heading stage (Cai and Luo, 1999;