What is the Process of Seed Germination? Seed germination explained I How do Seeds Grow? скачать в хорошем качестве

What is the Process of Seed Germination? Seed germination explained I How do Seeds Grow?

What is Seed Germination? Seed germination is the process in which different plant species grow from a single seed into a plant. One of the most common example of seed germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. Angiosperms are flowering plants, while Gymnosperms are a smaller group of plants that produce “naked seeds or seeds which are not protected by a fruit. The Process of Seed Germination The complete process of seed germination is carried out in the following steps: • In the first stage stage of germination, the seeds take up water rapidly which results in swelling and softening of the seed coat at an optimum temperature. This stage is referred to as Imbibition. It starts the growth process by activation of enzymes where the seed activates its internal physiology. It starts to respire, produces proteins and metabolizes the stored food. This is a lag phase of seed germination. • After the seed coat ruptures, radicle emerges to form a primary root. The seed starts absorbing water. After the emerging of the radicle and the plume, shoot starts growing upwards. • In the final stage of seed germination, the cell of the seeds become metabolically active, elongates and divides to give rise to the seedling. Conditions Necessary for Seed Germination Here are the important requirements and favorable conditions that are required for a seed to germinate into a seedling and to a plant. Water is necessary for the germination of seeds as it provides the necessary hydration, it provides dissolved oxygen for the growing embryo, softens the seed coats and increases the seed permeability. It also helps in the rupturing of seed and also converts the insoluble food into soluble form for its translocation to the embryo. Oxygen is an important and essential source of energy that is required for seed growth. It also helps in metabolism and is used as a part of aerobic respiration until the seed grows green leaves of its own. Oxygen can be found in the pores of soil particles, but if the seed is buried too deep it will be deprived of this oxygen. Germinating seeds respire vigorously and release the energy required for their growth. Therefore, deficiency of oxygen affects seed germination. Oxygen: In certain cases, a temperature below the moderate level slows down seed germination and promotes fungal growth. In some cases, germination stops at the temperature above the moderate level A moderate temperature of around 25-30°C and sunlight is required for the seed to germinate. Factors Affecting Seed Germination There are some major factors that affect seed germination. These include: Note that germination will not happen if the seed coat is resistant to water and gases, restricts water-uptake and oxygen exchange. The seeds with undeveloped or immature embryo do not germinate and certain seeds contain plant growth regulators, which inhibit seed germination. 1. Some seeds require more time for their germination.