Plant Propagation Creating New Plants

Sexual Reproduction (recap) Fusion of the pollen with the ovule to create an embryo found encased in a seed. Fusion of the pollen with the ovule to create an embryo found encased in a seed. Can select crops with desirable characteristics by choosing the ‘parent’ plants. Can select crops with desirable characteristics by choosing the ‘parent’ plants. What kind of characteristics do you think have been selected for in crops? What kind of characteristics do you think have been selected for in crops? Frost resistance, insect resistance, salt tolerance, drought resistance. Frost resistance, insect resistance, salt tolerance, drought resistance.

Certified Seeds Guaranteed to be free from pests and diseases. Guaranteed to be free from pests and diseases. Will give a good germination rate. Will give a good germination rate. What does ‘germination’ mean? What does ‘germination’ mean? The point at which the plant roots and shoots breaks out of the seed. The point at which the plant roots and shoots breaks out of the seed. Will also be free from weeds. Will also be free from weeds.

Vegetative Propagation Creates genetically identical plants. Creates genetically identical plants. Cuttings Cuttings Planting seed potatoes (tubers) Planting seed potatoes (tubers)

Cuttings A small part of a healthy plant is removed with a clean cut (stem, leaf or root). A small part of a healthy plant is removed with a clean cut (stem, leaf or root). Dipped in rooting powder, to cause new roots to grow. Dipped in rooting powder, to cause new roots to grow. Planted into moist soil (the cuttings have to be kept moist until the roots grow). Planted into moist soil (the cuttings have to be kept moist until the roots grow).

Advantages of Cuttings Plants are identical to parents – useful if the parent plant has a particular characteristic. Plants are identical to parents – useful if the parent plant has a particular characteristic. Plants such as fruit bushes will grow more quickly than those grown from seed. Plants such as fruit bushes will grow more quickly than those grown from seed. It can be used to propagate plants that do not produce proper seeds such as commercial varieties of banana and grapes. It can be used to propagate plants that do not produce proper seeds such as commercial varieties of banana and grapes.

Micropropagation Watch Presentation IA2.4 from section 4. Watch Presentation IA2.4 from section 4.

Micropropagation Uses tissue culture to grow many identical plants from tiny pieces of plant tissue. Uses tissue culture to grow many identical plants from tiny pieces of plant tissue. The surfaces of the pieces of tissue are sterilised and placed on a culture medium under sterile conditions. The surfaces of the pieces of tissue are sterilised and placed on a culture medium under sterile conditions. Kept in a room with controlled lighting and temperature. Kept in a room with controlled lighting and temperature. As they grow they are separated and transferred to an alternative growing medium. As they grow they are separated and transferred to an alternative growing medium.

The Advantages of Micropropagation Thousands of identical plants can be produced in a relatively small space. Thousands of identical plants can be produced in a relatively small space. The new plants are free from organisms that cause disease. The new plants are free from organisms that cause disease.

Your turn….. Using pages 24 and 25 in the text book (Agriculture and Food), answer the questions in the yellow box. Using pages 24 and 25 in the text book (Agriculture and Food), answer the questions in the yellow box. Copy down the diagram of Micropropagation from page 25 (with labels). Copy down the diagram of Micropropagation from page 25 (with labels).