3.3.2. Water

   3.3.2. Water

 

      Germination starts  when the seed absorbs water, starts to swell and the radicle or coleoptile emerges from the geminating embryo. Uptake of water is the first need for gemination. Germination may take two or more days depending upon the incubation temperature and dormancy of the seeds. The  Germination process may be subdivided into imbibition, activation, and postgermination. Under soaked condition of a seed, the seed rapidly absorbs water for the first 18 hours. This water intake increases the seed's water content to between 25 to 35%.  Germination occurs as a consequence of very active metabolic changes. Many activities go on inside the geminating seed. Starch, protain, and fat are changed into simple foods for the embryo. At the end of the activation stage, the tip of the coleoptile emerges from the ruptured seed coat. Subsequently, the coleoptile grows and the first leaf appears. Seeds are needed to soak for at least 24 hours for a more uniform gemination.