Phytochrome

Phytochrome
Definition
In the body of plant, there are certain compounds to get sunlight called Phytochrome.
OR
Special light sensitive pigments present in plant called Phytochrome.
Composition
These phytochromes consists of protein and a pigments.
Discovery
Phytochromes are light receptor, these are discovered in 1960.
Location
These are found in whole plant in little amount but these are abundant at growth tips.
Types of Phytochrome
These are two types of phytochrome
1. Phytochrome 660
2. Phytochrome 730
1. Phytochrome 660
Those phytochrome which absorbs red light having 660nm wave length are called phytochrome 660.
2. Phytochrome 730
Those phytochrome which absorbs infra red light having 730nm wave length care called phytochrome 730.
Effects of Red Light and Far-Red Light
Red Light
1. In this light phytochrome 660 is changed into phytochrome 730.
2. It increase the process of seed germination. E.g. Lettuce.
3. It help in the formation of plant pigment anthocyanine.
4. It increase the size of leaf.
5. It inhibit elongation of internode.
6. It promotes flower production in long day plant and reduced in short day plant.
Far-Red Light
1. In this light phytochrome 730 is changed into phytochrome 660.
2. It inhibits the process of seed germination. E.g. Germination
3. It prevents the formation of anthocyanine.
4. It decreases the size of leaf.
5. It increase the size of internode.
6. It promotes flower production in short day plant and reduced in long day plant.
Vitro Fertilization Plant
When the process of fertilization is performed outside the body of plant artificially by the help of scientific equipments it is called vitro fertilization.
Procedure

• In this process, ovules are removed from the ovary.
• They are placed in a solution containing all essential nutrients.
• After fertilization the zygote develops into embryo.
• When embryo matures, its development remains continue because it is autotroph.
• A new embryo matures when all necessary substances are provided to it like water and oxygen and suitable temperature.

Importance

• Vitro fertilization is important for new crops.
• In this process of development there is wider range of genotype.
• By this process there is better development of the plants which contain extra-ordinary genotype.

Asexual Reproduction in Animal
Asexual reproduction occurs in many ways. The common type in animals are
1. Fission
2. Budding
3. Regeneration
4. Parthenogenesis
5. Fragmentation
6. Cloning