Seed Germination
Definition of Seed Germination
The process where the seed sprouts for growing and developing into a plant.
More About Seed Germination
• Germination is a process when the seed develops into a seedling
• The seeds that germinate have an embryo inside it that grows into a new plant
• The process of germination starts with the seed absorbing water
• The absorption of water activates an enzyme that increases respiration
• The plant cell divide rapidly and the embryo inside the seed becomes large, and the radical (first root)of the plant emerges from the seed coat
• Various internal and external factors effect the seed germination
• The internal factors includes seed vitality, Genotype, Seed maturation and Seed dormancy
• There are many external factors affecting germination process as follows
◦ Water:
◦ The presence of the water is very crucial for the germinating process
◦ The seeds have an embryo, and stored food in the form of starch, proteins and oils enclosed in it
◦ Most of the seeds are very dry and need water for its growth
◦ The uptake of water by the seeds is known as ‘imbibition’
◦ All the cellular metabolic process occurring in the seed requires water
◦ The hydrolytic enzyme gets activated in the presence of water and the embryo grows, inside the seed coat utilising the food reserve
◦ The seed coat erupts and the radical come out slowly
◦ Oxygen:
◦ Oxygen is required for the metabolism occurring in the germinating seed.
◦ The oxygen is used in the aerobic process, which releases energy which is utilised by the seedling till the leaves appear.
◦ The seedling gets the oxygen from the atmosphere that is present in the soil pores
◦ Temperature:
◦ The optimum temperature is required for the germination
◦ As germination is a biochemical process and seeds germinate at a temperature slightly above 60o -75o F
◦ However, the temperature required varies from seed to seed, some above freezing point, some require cool, some need warm and some require alterations between the warm and cold temperature
◦ Light:
◦ Most of the seeds generally do not get affected by the light or darkness for germination
◦ However, light is essential in the later stage of the plant life cycle