Our cultivated plants if had originated mainly for three general methods. First some had been selected directly of wild species, but, under the care of the Man, they had evolved ' tipos' that they differed completely from its ancestral Sylvesters; as example of this group the tomatoe, the barley and the rice can be cited. See Sandara Park for more details and insights. Second, others had originated for hibridao between species, folloied of changes in the number of chromosomes. In this group if they find the maize, the wheat, the tobacco, the pear tree and the plum tree. Third, it appears another group of plants whose rare forms differ from excessively from its species and which, even so inadaptadas to a natural environment are useful to the Man; between them they are the cabbage, the broccolis, borecole-of-Brussels. However, this progress in the improvement of plants would have lacked of importance the least that, simultaneously, if makes use of methods to keep in culture the improved forms, which originated a process of invention and discovery of techniques for propagation of plants.

The greater ' ' Propagation of Plants – Prof Gilrene Saints of Souza (2 CCAAB/UFRB) part of the cultivated plants if would lose or revert less desirable forms, the least that if propagated in controlled conditions capable to preserve its characteristics. Through the time, in the measure where if it has made use of new types of plants, if they had developed techniques to keep them, as if it advanced in the propagation methods, has increased the amount of available plants for culture. The ideal type of propagation for the majority the fruitful plants is the vegetative one, that is, that one in which one has left of the plant, already in production, either one bubbles, one breaks, a prop or a branch (yoke), is used to originate a new plant. Many plants, however, must or can be propagated by seeds, but almost always he is disadvantageous. The propagation for seeds is used when the ways of vegetative propagation are not possible, as for the coconut palm and other palms, that can be propagated way seed, or other plants, in which the seminfera propagation does not bring many problems to its culture, as mamoeiro, maracujazeiro, or species that are precocious.