Question

Explain conditions influencing seed germination

Answer 1

1. Water
   • Water activates the enzymes and provides the medium for enzymes to act and break down the stored food into soluble form.
   • Water hydrolyses and dissolves the food materials and is also the medium of transport of dissolved food substances through the various cells to the growing region of the radical and plumule.
   • Besides, water softens the seed coat which can subsequently burst and facilitate the emergence of the radicle.
2. Oxygen
   • Germinating seeds require energy for cell division and growth.
   • This energy is obtained from the oxidation of food substances stored in the seed through respiration thus making oxygen an important factor in seed germination.
3. Temperature
   • The rate of germination increases with temperature until it reaches an optimum.
4. Enzymes
   • Enzymes play a vital role during germination in the breakdown and subsequent oxidation of food.
   • Enzymes are also necessary for the conversion of hydrolysed products to new plant tissues.
5. Hormones
   • Several hormones play a vital role in germination since they act as growth stimulators.
   • These hormones also counteract the effect of germination inhibitors.
6. Viability
   • ​​​​​​​Only seeds whose embryos are alive and healthy will be able to germinate and grow.