Plant Breeding Mass and Individual Selection
The selection of tree and shrub species is carried out according to economically valuable characteristics: growth rate, full-tree trunks, cleansing of trunks from branches, bark structure, often characterizing the physicomechanical properties of wood, and some others.
In forest breeding, two main methods of Selection are used – mass and individual. Both of these methods can be carried out with seed and vegetative propagation.
During seed propagation, mass selection is carried out by isolating, planting the best trees from which seeds are collected and used for sowing. With this method, the individual characteristics of the trees are not taken into account. He received the name of a single mass selection.
Such selection does not allow to obtain seed offspring with the strictly desired result, since it carries both maternal and paternal heredity due to cross-pollinated woody plants.
To increase the efficiency of a single selection, it is recommended to conduct it, selecting not the best trees, but the best bio-groups, thereby eliminating undesirable random paternal heredity.
Multiple (i.e., repeated in a number of offspring) mass selection gives significantly better results, but it can be applied only to valuable shrubs, early fruiting. It is almost impossible to obtain a similar practical result in tree species due to the long period of their cultivation.
During vegetative propagation, maternal properties and attributes are usually completely inherited. Mass selection during this reproduction is carried out by isolating the maternal individuals with positive qualities in the stand. From the selected specimens, cuttings are cut in various parts of the crown and planted together for subsequent reproduction without taking into account individual characteristics. The result is offspring that preserve maternal virtues.
The method of individual selection during seed propagation takes into account individual properties and characteristics, but for its application, as well as for mass selection, a long time is required.
The most promising for forestry is individual selection during vegetative propagation. For this, the planting is selected …