Grade - what is it: its characteristics

Having learned to cultivate plants, man began to make attempts to improve, preserve and reproduce the most qualitative forms. Even in ancient times, many varieties of wheat, grapes, various fruit plants were created. Thus arose the science of breeding new varieties of plants - selection.

Separation of varieties by descent

Variety - what is it? A variety is a stable group of plants created by selection methods and possessing hereditary characteristics within this group. Each plant variety is characterized by a combination of morphological, biological, economic characteristics that determine its characteristics. The variety description includes several characteristics. Origin indicates the source material used to create it. There is a huge variety of cultivated and wild plants, from which the necessary specimens are selected for breeding. This principle divides into two types such a capacious concept as a variety. What are its varieties - below. 1. Local - obtained by long-term selection, conducted by the population in a certain area. They are well adapted to the natural conditions of the region.

2. Selective - are created on the basis of scientific methods and, depending on the method of breeding, in turn, are divided into several groups:

• Variety-lines are obtained by individual selection of offspring from one self-pollinating culture, due to which they are characterized by the similarity of attributes and properties, but eventually lose this homogeneity due to mutations;
• Varieties-populations are usually local varieties formed by the method of mass selection of cross-pollinated crops, in which natural hybridization occurs simultaneously with other related plants;
• Clone-clones are the offspring of a single vegetatively propagated culture and are distinguished by high homogeneity and stability;
• Hybrid varieties form crosses of crops with a set of characters of several generations, selecting plants with the desired properties.

Biological signs

Selection grade. What does he mean by the following economic and biological signs?

1. Resistance to the influence of adverse natural factors:

• Winter-resistant - resistant to low temperature crops, suitable for growing in areas of the middle belt and more northern, depending on the variety;
• Drought-resistant - able to withstand a significant lack of moisture with minimal loss of yield.

2. The duration of the vegetative period is the period of time for which the plant must go through the entire cycle of its development. It depends on the type of culture, variety, thermophilic or cold resistance and many other factors. This is an important biological indicator necessary for proper zoning of crops.

3. Productivity is determined by the product of productivity, that is, the average yield of one plant, and the average number of plants located per unit area. For perennial woody plants, it is estimated already in adulthood, usually in kilograms from one tree.

4. Fertility characterizes the ability of plants to make ovaries during self-pollination. If this indicator is low or equal to zero, then there must be a plant next to it, which will become a pollinator for it.

5. Taste qualities differ depending on the content in fruits and berries of acids and sugars.

6. Resistance to pests and diseases is a very important quality for obtaining environmentally friendly products, since the treatment with pesticides leads to their accumulation in plants and in the environment. This direction in breeding is not only one of the main, but also the most difficult, since the potential for variability and the ability to reproduce in pests and pathogenic microorganisms is very high.

7. The ability of shoots to rooting is important, mainly for berry bushes.

External characteristics

The varieties differ in their morphological features:

• Coloring flowers;
• Shape and rugged edge of leaves;
• Height of the plant;
• For potatoes - the color of the skin and the shape of the tubers.

Over time, the new variety loses valuable properties, and scientific and technological progress in agriculture makes ever higher demands on crops, so the process of creating and improving varieties should be permanent.

Expertise of a new variety

So, a new variety is introduced. What is the legal protection of the International Union for the Protection of Selection Achievements? It is provided to protect the interests of breeders and the possibility of reimbursing the money spent by them. To obtain legal protection, this variety must undergo technical expertise, which includes three characteristics.

1. The criterion for distinguishing a variety is a photo, its description must be clearly different from any other one known at that moment.

2. The criterion of homogeneity of the variety - plants belonging to the proposed variety, should be the same for this method of reproduction.

3. Criterion of stability - all attributes and properties should remain the same after repeated breeding.

After a new plant variety passes all tests in a special area, it is assigned a varietal name and is added to the state register of breeding achievements.

The creation of new varieties provides humanity with more productive crops that are more resistant to many unfavorable environmental factors. Life puts forward a new variety of requirements for crops, so now methods are being developed to speed up breeding, which in the future will shorten the time for the introduction of new quality varieties of plants.