Hybridization as a Selection Method
II. Selection breeding
I. Analytical selection
At the first stages of industrial breeding, varieties of various crops were created by simply isolating them from the local best, most productive samples. For this, samples of local varieties (seeds) of a particular culture were collected in various farms, districts, regions. Further, these varieties were sown in a specially designated place in the test nursery and compared among themselves for a number of economically useful traits, yield, length of the growing season, resistance to diseases and pests, etc. After two or four years of evaluation, the best of them were prepared like new varieties. Moreover, the selection scheme was a very simplified version.
Breeders collected seeds of various varieties of a particular crop. Then these seeds were sown in a special nursery testing varieties of the first year. Sowing varieties was carried out with the same nutritional area with the same sowing period. During the growing season, plants were evaluated by the length of the growing season. An assessment was made of resistance to diseases and pests. After harvesting varieties were evaluated by productivity. After such a comparative evaluation, the most productive samples that were suitable for the breeder by a number of economically useful signs were placed the next year in the nursery for testing varieties of the second year. Varieties with low productivity and with undesirable economic and biological characteristics and properties were rejected. After two-four years of study, the most promising samples were placed in breeding nurseries. Subsequently, the seed material was sold to the producer.
In their breeding practice, during this period of breeding development, breeders used a two-year or four-year selection scheme. Naturally, with a four-year study, the reliability of the results was much higher than with a two-year study.