A review of mutagenesis breeding, the advantages and disadvantages of mutagenesis breeding

1. Advantages of mutagenesis breeding: many types of mutations, short time, and change fertility; Expanding the mutation spectrum and increasing the mutation rate The general mutagenesis rate is about the same, and a variety of mutagenesis factors are that the mutation rate is increased to 3%, which is 100 1000 times larger than the natural variation. It is more effective to improve individual single traits, but it is more difficult to improve multiple traits at the same time, and it is difficult to effectively improve single traits such as maturity, lodging resistance, dwarf stalk, and disease resistance of promoted varieties.

The induced variants are easier to stabilize, and most of the variants induced by shortening the breeding period are changes in a major gene, which are stable and relatively fast, and are generally basically stable after 3 or 4 generations.

2. Disadvantages of mutagenesis breeding: it is easy to cause harm to the human body, and most of the chemical mutagens are toxic substances, and the safety is not high, so it is difficult to determine the direction of mutation of mutagenesis. low frequency of beneficial mutants produced by mutagenesis; difficulty in effectively controlling the direction and nature of variation; In addition, it is difficult to induce and identify micromutations in quantitative traits.

The advantage of mutagenesis breeding is that it can increase the mutation rate and obtain more excellent variant types in a shorter period of time. The limitation of mutagenesis breeding is that it is difficult to grasp the direction of induced mutations, and it is difficult for mutants to concentrate multiple desirable traits. To overcome these limitations, it is possible to expand the population of mutagenic offspring and increase the chances of selection.

What are the advantages and disadvantages of mutagenesis breeding.

Advantages: Accelerates the breeding process and greatly improves certain traits.

The basic principle of mutagenesis breeding is genetic mutation, which mainly includes chromosome aberration and genetic mutation. Mutagenesis breeding is a breeding method that uses various physical factors and chemical agents called mutagens to treat microbial cells, increase the frequency of gene mutations, and then obtain the required high-yield and high-quality strains through appropriate screening methods.

The main problem of mutagenesis breeding is that the frequency of beneficial mutations is still low, and the direction and nature of mutations are still difficult to control. Therefore, the mutagenesis efficiency can be improved, and the mutant can be quickly identified and screened, and the pathway of directional mutagenesis can be explored.

Advantages of mutagenesis breeding:

It is able to increase the mutation rate and obtain better mutation types in less time.

Disadvantages of mutation breeding:

It is difficult to grasp the direction of induced mutations, and it is difficult for mutants to concentrate on a variety of desirable traits. By overcoming these limitations, you can expand the mutant offspring population and increase your chances of selection.

The above content refers to the Encyclopedia - mutagenesis breeding.

The mutagenesis breeding steps mainly include mutagenesis and screening, in which the mutagenesis process includes: selection of the starting strain, preparation of single spore or single cell suspension, selection of mutagenesis and mutagenesis dose, mutagenesis treatment, etc.

Mutation breeding uses physical, chemical and other factors to induce mutations in organisms under artificial conditions, and selects them to breed new varieties of plants, animals and microorganisms.

The basic steps of mutagenesis breeding: strain initiation, purification, synchronous culture, bacterial suspension, mutagenesis treatment, plate separation, inclined plane, preservation and expansion experiment.

The main problem of mutagenesis breeding is that the frequency of beneficial mutations is still low, and the direction and nature of mutations are still difficult to control, so improving the mutagenesis efficiency, rapidly identifying and screening mutants, and exploring the ways of directional mutagenesis are important topics in current research.

Mutagenesis breeding uses physical and chemical factors to induce the genetic characteristics of animals and plants to mutate, and then selects a single individual that meets a certain requirement of people from the mutant population, and then cultivates a new variety or germplasm breeding method, it is a modern breeding technology developed after selective breeding and hybrid breeding.

Answer: Mutagenesis breeding is the use of physical or chemical mutagens to treat uniformly dispersed microbial cell populations, promote their mutation rate to increase significantly, and then use simple, fast and efficient screening methods to select a small number of mutant strains that meet the purpose of breeding for production practice or scientific research.

At present, the high-yielding strains used by the fermentation industry and other production units are almost all strains that have greatly improved their production performance through mutagenesis breeding.

In addition to increasing yield, mutagenesis breeding can also achieve the purpose of improving product quality, expanding varieties and simplifying production processes.

The mutagenic breeding of rolling slag varieties is still one of the main breeding methods widely used at present, because of the characteristics of simple method, rapid and remarkable results.

Mutations of various traits can be carried out spontaneously without human factors, but the mutation rate of spontaneous mutations is very low, and the possibility of obtaining mutant strains that meet the requirements is very small.

Under the action of artificial physical and chemical mutagenesis factors, the mutation rate of the strain was greatly improved, and the possibility of mutant strains with favorable traits being screened was greatly enhanced.

These physicochemical mutagenic factors are also called mutagens.

The ability of wild-type strains isolated directly from nature to accumulate products is often low and cannot meet the needs of industrial production, which requires them to be modified by strains, i.e., breeding.

There are many breeding methods, from the history of the development of microbial breeding, there are directional breeding, mutagenesis breeding, hybrid breeding, cell fusion and genetic engineering and other breeding technologies.

At present, mutagenesis breeding is still one of the most effective and practical methods for microbiologists.

The specific steps are as follows:

The mutagenesis process produces a good mutagenic generation, which is denoted by m1. Due to the inhibition and damage of mutagenic factors such as radiation, the germination rate, emergence rate, adult plant rate and seed setting rate of M1 are generally low, the development is delayed, the plant is dwarf or deformed, and chimeras appear.

But these changes are generally not passed on to future generations. Most of the genetic variations caused by mutagenesis are recessive, so M1 is generally not selected and harvested as a single plant, single spike or treatment.

The second generation of mutagenesis (M2) is the generation with the greatest variation, and it is also the critical period of selection, and the excellent single plant (panicle) can be selected according to the breeding goals and genetic characteristics of the traitMost of the variations are unfavorable, but there are also beneficial variations such as early maturity, short pole, disease resistance, stress resistance, and good quality in the lead belt per mu, and the frequency of variation is about.

After three generations of mutagenesis (M3), with the increase of generations, the segregation of traits decreases, and some traits can be quickly stabilized once acquired. After several generations of selection, stable and excellent mutant lines can be obtained, and new varieties can be further experimented with. Mutant lines with certain prominent traits can also be used as hybrid parents.