PRACTICAL APPLICATIONS IN PLANTS

cutting

Another basic method of growing plants asexually is using cuttings. A cutting is some portion of a plant that may be cut off and planted to grow a new plant. The most common kind of cutting is the stem cutting. In this technique a section of stem is cut from a plant and placed in soil or growing medium. Roots grow from the base of the cutting and a new plant is established. Roots which grow from stem tissue are termed adventitious roots. The various kinds of stem cuttings range from those taken from soft, green tissues at the end of a stem to hard, woody ones taken farther down the stem. Different kinds of stem cuttings are used in growing different kinds of plants. Many of the nursery plants in containers, such as shrubs, are grown from cuttings. A second type of cutting is a root cutting. In root cuttings a section of root is cut from a parent plant and planted. It will then grow a new plant. The root cutting must develop adventitious buds. Root cuttings are not as widely used as stem cuttings. A third kind of cutting is a leaf cutting. A leaf or a piece of a leaf is planted, and it develops both adventitious buds and adventitious roots. A few kinds of plants already have buds which are present in the leaf, especially in the notches around the margin. The kalanchoe with its development of many tiny plants around the notched edge of the leaves is an example.

root cutting

A cutting made from the root of a plant which develops adventitious buds and grows into a new plant.

stem cutting

A cutting of stem tissue used to grow a new plant.

budding

A kind of asexual reproduction involving the growth of a new individual from part of an older organism. It can also refer to uneven distribution of cells that results in one cell receiving most of cell contents. In grafting, budding involves reducing the scion to a singular bud.

leaf cutting

A technique in horticulture using a cutting made from a leaf or leaf tissue to grow a new plant.

grafting

A technique used in horticulture in which a part of the stem or a bud is inserted into a plant with a good root system. The inserted portion of the stem or the bud then becomes the top part of the plant, and it uses the root system it was grafted into.

Layering

One method used in the reproduction of plants is layering. Layering is a technique in which a stem of a plant is bent to the ground and a portion of it buried. (It was probably first tried because many plants will root from the stem if they touch the ground.) The growing tip of the stem is not buried. The stem is sometimes cut or injured at the underground section to stimulate rooting. After roots form, the new plant is cut away from the parent plant to be planted elsewhere. Another method of layering consists of placing wet peat moss or something similar around a partially cut stem and keeping it moist until roots form. The peat moss is often covered by a plastic bag so that moisture will be kept in the area where roots will form. Some food crops using layering techniques include the filbert, gooseberry currant, muscadine grape, the litchi (a small nut-shaped fruit grown on a tree in warm regions of the world), and some blackberries.

grafting

The last type of asexual reproduction to be considered is grafting. Grafting is a technique involving the placement of a desired plant stem or bud into another plant that has a developed root system. The plant with the root system is called the stock, or the rootstock. The portion of a plant with buds that is placed into the stock is called a scion. Grafting is extremely important to man, especially in the growing of fruit trees and many kinds of flower-bearing, woody plants. Grafting offers several advantages to man. Through grafting vigorous rootstocks that would not produce fruit or flowers of good quality or great amount can be used. Many valuable fruits and flowers do not produce good root systems, but they are grown on a good rootstock and bear well. A second major advantage of grafting is found in the uniformity of the plants produced. All of the offspring have the same characteristics. If you were to grow apples, oranges, or some other kind of fruit, you would probably want all of the fruit to ripen at about the same time and to have the same characteristics. If some trees in a peach orchard produced delicious fruit and others produced woody fruit or some peaches were a pale yellowish-green and others were bright yellow with a red blush, selling the fruit for a good price would be difficult. Some kinds of plants are reproduced from one generation to the next only by grafting. The Washington naval orange is an example of a fruit that is reproduced almost entirely by grafting. The Bartlett pear has been preserved by grafting since the eighteenth century. Some kinds of plants that cannot root or have poor root systems must be preserved by grafting. If a particular kind of fruit or flower is developed it may be preserved by the use of grafting, especially if it cannot reproduce by seeds. Grafting also permits some control over the size of certain plants. Certain combinations of scion and rootstock may grow to full size, or they may be dwarfed. Many techniques of grafting exist. If the scion is reduced to a single bud the kind of grafting is termed budding. Budding is commonly used in the production of fruit trees of desired varieties. Note that the term is used differently than it was in discussing budding in animals or in yeasts

scion

The portion of a plant with buds, that is placed into the stock by grafting or budding.

root stock

The portion of a plant with the root system used in grafting.

layering

The technique of developing roots on a stem of a plant while that stem is still attached to the parent plant. After a new root system is established the new plant is cut away from the parent plant and planted.

A root which develops from stem or leaf tissue instead of root tissue is said to be

adventitious

A successful scion will produce the product of the rootstock with greater quality.

false

An advantage of grafting is to increase the quality of the rootstock.

false

The new plant produced by the technique of layering must remain attached to the stem of the original plant.

false

A successful cutting requires that the new plant acquire its own

root

The part of a desired plant inserted into rootstock during grafting is called the

scion

(Select all that apply.) Cuttings used for growing plants may be taken from which of the following?

stems leaves roots

Grafting is an ancient practice.

true

If you develop a particular flower which cannot be reproduced from seeds, it could be preserved by grafting.

true

"And they also, if they abide not still in_____, shall be______in: for God is able to_______them in again. For if thou wert cut out of the olive tree which is wild by nature, and wert graffed contrary to nature into a good olive tree: how much more shall these, which be natural branches, be graffed into their own olive tree." Romans 11:23-24

unbelief; grafted; graft