PLANT PROPAGATION PLANT REPRODUCTION

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1 PLANT PROPAGATION Propagation is the process of growing new plants from existing plants (even kitchen scraps sometimes). It is one of a gardener's best friends. Plant propagation can be done through seeds, cuttings, bulbs, or other plant parts. It also refers to the natural or artificial dispersal of plants. PLANT REPRODUCTION Plants reproduce both sexually and asexually. Sexual reproduction is done through a process called germination it increases genetic diversity, but takes a long time. Asexual reproduction happens in a process called vegetative reproduction, where a new plant grows from an existing plant part (leaf/stem/root). It takes less time to mature into an adult plant, but maintains genetic consistency. Plant propagation can occur both naturally and artificially.

2 NATURAL PROPAGATION Most seeds go through a state of quiescence (inactivity/dormancy) where there is no active growth. During this time, a seed can be transported safely to a new location (wind, water, insects, other animals) and/or survive adverse climate conditions until conditions are favourable for growth. Under favourable conditions (ideal temperature, water, oxygen, and sometimes light or darkness), the seed begins to germinate and the embryonic tissues resume growth, developing into a seedling. Mung Bean Seeds Sprouting ARTIFICIAL PROPAGATION It is possible to harvest seeds for artificial dispersal of plants. The seeds must be forced to come out of dormancy (or made to germinate), though this is not an easy task. Some seeds have a physical or chemical inhibitor to prevent germination at an improper time. In some cases, though, this can be overcome by pre treatment of the seed this includes boiling water, smoke, fire, abrasion, or soaking.

3 NATURAL VEGETATIVE PROPAGATION Vegetative Propagation There are several different types of modified stems/roots/leaves that can propagate. STOLONS (RUNNERS) Stolons are horizontal, above ground stems that produce new plants when they touch the ground. They have buds where new plants grow from. Strawberries are the best example of runners. TUBERS Swollen, modified roots called tubers can grow into new plants as well. Potatoes are the best example of this. Buds develop at the base of the stem, which grows into a new plant.

4 CORMS Also a modified root, a corm is a bulbous underground structure that will grow into a new plant. These plants tend to be very short and include gladiolus and crocus. BULBS A bulb contains an underground stem. Leaves are attached to the stem and they contain a lot of stored energy. Many common vegetables are bulbs (onions, garlic, leeks). LEAVES Some leaves are capable of growing into a new plant. New plants grow from plantlets on the edge of their leaves.

5 ARTIFICAL VEGETATIVE PROPAGATION Horticulturists and farmers use artificial means to produce plants that are identical to the parent plant. They use multiple methods: CUTTING A cutting is a piece of a plant that under suitable conditions will initiate root growth. The most important factor is to keep the cutting moist. Sometimes a growth promoter (hormone) may be used. Cuttings can be done from the root, stem, or leaf level. Each one would require the plant to then develop the missing components. GRAFTING Grafting can be done to combine desirable traits from two parent plants. The scion (cut portion of the above ground plant) is attached to the stock (rooted portion of the second plant). Plants of the same species tend to graft quite easily. Two plants in the same genus are less reliable to graft, while plants of the same family are even less reliable. LAYERING In layering, a shoot of a parent plant is bent until it can be covered by soil. The tip of the shoot remains above ground and new roots and eventually a new plant will grow. How to take a cutting Timeline of cuttings