It is difficult to overestimate the importance of the underground organ of plants. After all, it reliably holds even huge trees in the soil, provides them with water and an adequate supply of nutrients. Sometimes environmental conditions require additional functions. And then the root is modified.
The root and its structure
According to the structural features, several types of roots are distinguished. The main root acts as a rod. It is easy to distinguish from others. In a plant, he is always alone. Lateral depart from the main root. They are necessary to increase the surface area of the soil in order to be able to absorb more moisture. The root system, consisting of such roots, is called the core. Roots that grow directly from the shoot (the aerial parts of the plant) are called subordinate. Their bundle forms a fibrous root system.
Modification of plant roots
The classical structure of the root system makes it possible to perform only certain functions. To survive plants in difficult conditions, root modification is necessary. Let's consider each of them in more detail.
Roots
Everyone remembers the tale of the tops and roots. Such root modification as root crops is an example of tasty and juicy roots. Carrots, radishes, turnips, beets ... It is impossible to imagine one day without the presence of these wholesome and tasty foods in our diet.
They are the result of thickening of the main root of the rod system. In order to survive the cold autumn and winter and form seeds, a plant underground stores water with minerals. A person uses juicy root vegetables for food.
Root tubers
What is a modification of the root can also be considered on the example of root tubers. This is also a thickening of the roots. But not the main thing, but the accessory roots of the fibrous system. As a result, the underground beam becomes powerful and heavy due to the significant supply of water. It is found in dahlia, asparagus, cinquefoil, sweet potato.
An additional function of root tubers is vegetative propagation. It is possible due to the presence of accessory kidneys on these modifications, which are often called root cones.
Aerial roots
The conditions for the growth and modification of the roots are inextricably linked. Plants of equatorial forests grow in conditions of high humidity. Such plants do not need to get moisture out of the soil, since it is enough in the air. For example, an orchid grows directly on tree trunks from which aerial roots hang. Absorbing water directly from the air, they provide the plant with this necessary substance with the help of air (respiratory) roots. Ficus, Crassula, Monstera - indoor plants, which also form aerial roots. For their normal development, sufficient humidification of the air in the room is necessary.
Props
A modification of the root is the root-backup. The name itself speaks of the functions it performs. Indeed, strong accessory roots, like artificial fastening, keep the shoot. They can often be seen in corn. The shoot of this plant with fruits is quite weighty. And the fibrous root system has quite superficial roots that are not able to hold the plant during strong gusts of wind. Here a special device comes to the rescue - roots-props.
Many people saw a man on stilts in the circus, but in nature you can find plants on such devices. The stilted roots look like props, but grow from the shoot down. In mangroves of tropical forests, they additionally perform the function of absorbing moisture from the air. They seem to raise the plants of the tidal zone above the water, ensuring their normal functioning.
Trailer Roots
The well-known ivy is able to occupy any surface. Even a vertical rock will not be a special obstacle for him. He acquired this ability due to the presence of clipping roots-trailers that can attach to any surface.
Gaustoria
In parasitic plants, a modification of the root is a haustoria or sucker root. Rafflesia beauty, having a very large flower, is incapable of photosynthesis. Therefore, it cannot provide itself with organic substances. Where to get them? Of course, in another plant. With the help of suction cups, rafflesia penetrates the roots and stems of tropical vines, sucking ready-made substances from them. Surprisingly, this plant consists only of mutated roots and a giant flower.
There are also semi-parasite plants. For example, mistletoe is capable of photosynthesis and itself produces the required amount of sugars. But the water and the nutrients dissolved in it are received not from the soil, but from other plants with the help of sucker roots.
Mycorrhiza
Everyone knows that boletus grows under birch, and boletus under aspen. But not everyone knows why. The fact is that the roots of some plants mutually coexist with fungi. From such a symbiosis is good for everyone. Mushrooms receive organic substances from a tree that they cannot produce on their own, as they are incapable of photosynthesis. And the trees with the help of mushrooms are provided with water with a solution of inorganic substances.
Modification of the root helps the plant survive in conditions of deficiency or excess moisture, it is better to stay in the soil, attach to the support and remain viable for a long time, giving an excellent harvest.
Man has long learned to use them in his activities. Root crops containing a large amount of valuable vitamins and minerals are used in food. And not only in raw, but also in boiled, fried and canned form. Feed varieties of beets and turnips are grown for livestock. From a special type of beet, sugar is obtained by processing. But parsley is valued not for the bitter root, but for the juicy and healing leaves of the shoot. So, mutating, the roots benefit not only plant, but also animal organisms and humans.