Excluding the limitations of traditional breeding technology, what are the traditional breeding methods?

The lack of breakthrough genes is not usually included in the limitations of traditional breeding techniques, which refers to the use of older breeding methods and natural breeding processes to create new biological varieties. A method that attaches great importance to the utilization and research of hybrid vigor, and uses different technical means to continuously concentrate various excellent genes that are beneficial to improving grain yield and quality into a certain variety, thereby increasing crop yield and resisting disasters However, the resistance obtained by this method is generally easily affected by the variety and regional environment. For example, the resistance of new stress-resistant varieties bred from the north may not be obvious in the south.

1. Limitations of traditional breeding technology do not include

1. What does not include

The limitations of traditional breeding technology generally do not include the lack of breakthrough genes.

2. Introduction to traditional breeding

(1) Generally, the method of using older breeding methods and natural breeding processes to cultivate new biological varieties is called traditional breeding.

(2) Traditional breeding usually attaches great importance to the utilization and research of hybrid vigor, and uses different technical means to continuously gather various excellent genes that are beneficial to improving grain yield and quality into a certain variety, and then Allow it to obtain relatively high yields and improve its ability to withstand disasters such as drought.

(3) However, the resistance obtained through traditional breeding is usually easily affected by the variety and regional environment. For example, if a new stress-resistant variety bred in the north is planted in the south, it may Its stress resistance will not be too obvious.

2. What are the traditional breeding methods?

1. Cross-breeding

(1) After crossing the parents, different genetic diversity is formed, and then By screening the hybrid offspring, you can obtain new varieties that have the excellent shapes of the parents but without the bad traits of the parents. This breeding method is cross breeding.

(2) The advantage of this breeding technology is usually that it can obtain new varieties that are stronger or perform better than the parent varieties, but the disadvantage is that the hybrid offspring will have segregation of traits, making the hybrid crops difficult to produce. It is suitable for seed saving, and the breeding process is relatively slow and complicated.

2. Mutation breeding

(1) Using physical, chemical and other factors to induce variation in the genetic characteristics of animals and plants, and then selecting from the mutant population To produce a single plant or individual that meets certain people's requirements, and then breed it into a new variety or germplasm. This breeding method is usually called mutation breeding.

(2) Although this method can increase the mutation rate in a shorter time and obtain better mutation types, the direction of inducing mutations is difficult to master, and the mutants are relatively It is difficult to concentrate on multiple ideal traits.

3. Haploid breeding

(1) Use plant tissue culture technology to induce haploid plants, and then use some means to double the chromosome set, and then Then let the plant return to its normal chromosome number, and this breeding method is haploid breeding.

(2) Haploid breeding can usually improve crop varieties. Our country has used this method to develop some excellent varieties such as rice and wheat. If it is combined with hybrid breeding and other methods, it can Enhance the effectiveness of improved crop varieties.

4. Polyploid breeding

(1) The purpose of obtaining polyploid breeding materials is to use artificial mutagenesis or natural mutation and doubling of cell chromosomes. It lies in the ability to select and breed superior varieties that meet people's needs, and this method is called polyploid breeding.

(2) The advantages of polyploid plants are thick stems, generally larger leaves, fruits and seeds, and higher sugar and protein content. However, the disadvantages are delayed development and low seed setting rate. .