What is the change of genes in traditional breeding?

Traditional breeding is the change of genes in combination.

Traditional breeding techniques include cross breeding, polyploid breeding (haploid breeding), mutation breeding (physics), ultraviolet mutation, chemical mutation, and now ion beam breeding.

Characteristics of traditional breeding:

Traditional breeding attaches great importance to the utilization and research of heterosis, and its ultimate goal is to gather all kinds of excellent genes that are conducive to improving grain yield and quality into one variety through different technical means, so that it can obtain higher yield and resist disasters such as drought.

Defects brought by traditional breeding:

1. The transfer of agronomic traits is easily restricted by interspecific reproductive isolation, and the genetic resources of related or distant species cannot be used for genetic improvement of selected crops. Excellent genes between different species are difficult to use.

2. Gene transfer through sexual hybridization can't accurately operate and select a gene, which is easily affected by bad gene linkage. In order to get rid of the influence of bad gene linkage, it is necessary to detect multi-generation and large-scale genetic segregation population. Therefore, while gaining some excellent resistance, it may affect the fertility of plants.

3. The success of sexual hybridization gene transfer generally depends on apparent variation or bioassay, and the detection efficiency is easily affected by environmental factors.

4. The resistance obtained by traditional breeding is easily influenced by varieties and regional environment. That is, new varieties cultivated in the north may not show obvious resistance when planted in the south.