Question

How does light affect seeds germination?

Answer 1

Seed germination:

1. Seed germination may be defined as the fundamental process by which different plant species grow from a single seed into a plant. This process influences both crop yield and quality.
2. A common example of seed germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm.

Effect of Light:

1. The timing of germination in the field can be influenced by seed reactions to light, which can have an effect on seedling survival as well as development and fitness in later life stages.
2. Small seeds that need light to germinate are typical.
3. Seeds sown under high light intensity had a lower germination percentage than seeds subjected to low light intensity and darkness.
4. A seed may need light to germinate at a certain temperature but not at other temperatures, which indicates that temperature plays a significant role in modifying seed responses to light.
5. For some species, temperature variations can completely or partially replace the need for light.
6. It is generally known that phytochromes facilitate light-promoted germination and that they enhance the number of bioactive gibberellins in seeds.
7. In the dark, exogenously administered gibberellins encourage the germination of photosensitive seeds.
8. Conversely, nitrates which are naturally occurring in the soil, can also substitute for the light requirement in some cases.