The grains of rice varieties that lack dormancy
germinate immediately upon ripening. In dormant
varieties, a rest period precedes germination and
special procedures such as heat treatment (50°C.
for 4-5. days) or mechanical dehulling are needed
to break dormancy in freshly harvested samples.
The coleorhiza enveloping the radicle protrudes
first if germination occurs in an aerated environ- ment such as a well-drained soil. If the grain is
submerged in water, the coleoptile emerges ahead
of the coleorhiza.
The primary seminal root (radicle) 1 breaks
through the coleorhiza shortly after the latter ap-
1Term in parenthesis indicates a synonym.