Tuber is a modification of the shoot
Value of modifications
Why do plants generally make modifications? After all, all vital functions provide their organs. Just under certain conditions, this is not enough. Tuber is a vivid example of such a case. Examples of shoot modifications are rhizome and bulb. Their main function is nutrient storage and vegetative reproduction.
Some mistakenly believe that a tuber is any thickened part of a plant. But this is not at all the case. Tubers are underground shoots. They grow from the base of above-ground stalks. Such shoots are also called stolons. By origin a tuber is its apical thickening.
Proving that a tuber is an escape is very simple. Its main part is a thickened stem. It contains the kidneys, which are called "eyes". Leaves develop from them. This structure allows the use of tubers for vegetative reproduction. It is found in potatoes, Jerusalem artichoke, and crested hen.The tuber has short internodes and does not contain chlorophyll, but if left in the light, it can turn green. The fact is that the main storage tissue of tubers contains leukoplasts. These are colorless plastids. Under the action of light energy, they turn into green - chloroplasts.
In nature, tubers are often found that are modifications of the underground organ of plants. They appear as a result of thickening of adventitious or lateral roots. Examples of plants for which such structures are characteristic are yam, or sweet potato, chistyak, dahlia.
The most famous tuber is the potato. Its homeland is South America, where initially this plant was wild. In Europe, he was brought toXVI thcentury. But in Russia at first they disliked potatoes. The peasants called him a "damn apple." Even so-called “potato riots” are known in history.
Now this vegetable is called the "second bread". But in the case of potatoes from love to hate - hundreds of years. 25% of this product consists of starch, which accumulates in leukoplasts. Therefore, potatoes have a high calorie content.In much smaller quantities, this vegetable contains fats and amino acids that make up the full-fledged proteins. Of the valuable minerals can be called magnesium, calcium and iron.