In the process of evolution, nature invented the following ways of plant reproduction: seed and vegetative.
The latter suggests the possibility of obtaining a new individual from some part of the plant. This is a kind of cloning. The plant reproduces its exact copy. There are significant advantages in this - usually species that reproduce in this way are unpretentious, resistant to changes in the environment, adapt well to them. But there are certain disadvantages - they can not occupy vast territories, since there is no mechanism for moving the child over long distances, it is tied to the mother plant.
Seed (there are male and female flowers) reproduction appeared later, it gave impetus to the resettlement of vegetation on the surface of the Earth. Yes, this reproduction does not have stable results, it depends very much on the conditions in which the seeds fall. But plants have found a way to solve this problem. They produce seeds several times more than necessary, making an amendment to the fact that 60% of the plant simply will not be able to develop. So the chances were equal. It happens that some representatives of the flora can use different types of plant reproduction. For example, strawberries are mostly propagated by shoots, but few know that it gives seeds.
The methods of plant reproduction were based on people, when they guessed that it was possible to create new varieties with improved qualities. Thus was born the science of selection. Of course, it's rather difficult to get a new variety of a plant that reproduces with seeds. This is a long and painstaking work. Just imagine: the breeder must cut off the male flowers on some plants, then to pollinate them with the flowers of others, in addition, to do it in large areas. Such patience can only be envied. Easier with cross-pollinated - they are just planted next to them and selected the necessary specimens. This, of course, is easier, but practice shows that the results of such selection are rather unstable.
But the methods of vegetative propagation of plants give more stable results. These include breeding with shoots, cuttings, rhizomes, Tubers and bulbs. These methods of plant propagation are widely used by gardeners who are engaged in berry, flower and fruit crops. Moreover, this procedure is simple and gives 80-85% of the successful result. For example, many fruit trees reproduce with root shoots. In addition, grafts of cuttings of one sort are often used for growing trees or saplings that have been adopted. Raspberry propagates by root processes. Get a new bush of currants can be, sprinkling the ground with the lower branches. A strawberry with cosmic speed gives a mustache. If you calculate how much you can get from one bush, you get 200 pieces. Of course, as practice shows, not all these plants will yield a stable crop, so gardeners do not give strawberries to multiply at this rate. But the scale is impressive.
Using all methods of plant propagation, a person has the opportunity to regulate the number of species in his own hands, which allows to solve the problem of the sustenance of a steadily growing humanity.