Agriculture Reference
In-Depth Information
2
SEED GERMINATION
Seed germination is the initial step of plant life cycle. A small
seed grows into a plant in the long run and produces many
seeds. So the multiplication process goes on. In the meantime
the plant gets adapted and the genomic changes in it.
Conditions essential to germination are water, air,
temperature and light. For rice seed germination, quiescent
or nondormant, seeds require only rehydration after release of
primary dormancy. The main gas affecting seed germination
is oxygen, but ethylene and to a much lesser extent, carbon
dioxide can also do so. The oxygen requirement for seed
germination depends greatly on other environmental factors,
such as temperature, light and water potential. The higher the
temperature the richer is the oxygen in the atmosphere for
seed germination. However, rice seeds have been mentioned
as being able to germinate in complete anoxia (Bewley et al.
2006). Except in few cases, the germination of rice seed has
been known to be unaffected by light or darkness. However,
the germination of rice seed is affected greatly by temperature.
Cold temperature reduces seed germination starting from
imbibition, activation and subsequent manifestation. Cold
temperature not only reduces germination but also slows down
the germination process.
