Does Plant Breeding Result In Genetic Variation Through Mutations?

Plant mutation breeding, also known as variation breeding, is a method that uses physical radiation or chemical means to induce spontaneous genetic variation in plants to develop new crop varieties. Mutations are the source of most genetic variation and the motor of evolution, with genetic diversity affecting various characteristics of a plant species. These mutations can have neutral, positive, and negative impacts on various characteristics of a plant species.

Plant evolution and genetic breeding depend on genetic variation that not all come from spontaneous mutation but comes by genetic recombination. Mutation is a heritable change in the genetic material of living organisms and is a major driver of species diversity and evolution. Recent breakthroughs in whole genome-based mutation detection technologies increase the efficiency and precision of breeding in all crops, while in vitro techniques coupled with mutagenesis broaden the genetic base. Mutational breeding provides a pathway to overcome these constraints by deliberately triggering genetic variations in plants.

Plant breeding plays a significantly important role in ensuring the introduction of new traits in breeding programs. However, mutation breeding has evolved from relying solely on forward genetics, i.e., phenotype screening for favorable traits in mutant populations. The presence of genetic variation is a key prerequisite for genetic improvement in plant breeding and plays a pivotal role in germplasm usage in breeding.

Mutation breeding is an advancement of plant breeding where the induction of physical and chemical mutagens causes genetic variation. These mutagens can occur at all levels of genetic organization, classified mainly as either chromosome or chromosome-specific.

In conclusion, plant breeding relies on broad genetic variation, which can be produced through targeted or random mutagenesis.

Is genetic variation caused by mutation?

Evolution is the process by which organisms change over generations, with genetic variations playing a crucial role in this change. Genetic variations can arise from gene variants or from a normal process called genetic recombination. These variations alter gene activity or protein function, introducing different traits that help individuals survive and reproduce. If these traits are advantageous, they are more likely to be passed on to the next generation through natural selection.

However, not all genetic variants influence evolution. Hereditary variants, which occur in egg or sperm cells, can be passed to future generations and potentially contribute to evolution. Some variants occur during a person’s lifetime in only some of the body’s cells and are not hereditary, so natural selection cannot play a role. Many genetic changes have no impact on the function of a gene or protein and are not helpful or harmful.

The environment in which a population of organisms lives is integral to the selection of traits. Some differences introduced by variants may help an organism survive in one setting but not in another, such as resistance to a certain bacteria.

Some harmful traits, like genetic diseases, persist in populations instead of being removed by natural selection. For example, Huntington’s disease can be passed on despite being harmful due to later signs and symptoms. Reduced penetrance, where some individuals with a disease-associated variant do not show symptoms, can also allow harmful genetic variations to be passed to future generations.

In some conditions, having one altered copy of a gene in each cell is advantageous, while having two altered copies causes disease. This disease resistance helps explain why variants that cause sickle cell disease are still found in many populations, especially in areas where malaria is prevalent.

What are the 4 main sources of genetic variation?

Genetic variation is a crucial factor in evolution, allowing natural selection to alter the frequency of existing alleles in a population. It can be triggered by mutations, random mating, fertilization, and recombination during meiosis. This variation is beneficial to a population as it allows some individuals to adapt to the environment while maintaining the population’s survival. Genetic diversity refers to the total number of genetic characteristics in a species’ genetic makeup, while crossing over involves the exchange of genetic material between homologous chromosomes, resulting in recombinant chromosomes.

Phenotypic variation, a fundamental prerequisite for evolution by natural selection, is a result of underlying heritable genetic variation. Genetic variation measures genetic differences within a population, and it is essential for natural selection as it can only increase or decrease the frequency of existing alleles.

How do you create variation in plant breeding?

Plant mutation breeding, also known as variation breeding, is a method that uses physical radiation or chemical means to induce spontaneous genetic variation in plants to develop new crop varieties. Mutation is a natural process that occurs spontaneously and slowly over generations in people, plants, animals, and all living beings. It involves altering DNA, leading to the development of changes within the organism. Mutation can be sped up by chemical or physical methods, such as radiation (irradiation), to achieve characteristics useful in agriculture.

Irradiation can produce plant varieties with improved qualities, such as higher yields, shorter cultivation times, and resistance to diseases, pests, and climate change effects. Cultivation and popularization of these plant varieties help make global food production more stable and address the needs of farmers, particularly in developing countries and regions most vulnerable to climate change impacts.

Radiation-bred plant varieties are equally safe as those developed through conventional or marker assisted breeding, allowing plants to be bred for many generations without damage or becoming radioactive.

What is the main source of genetic variation?

Genetic variation is defined as the occurrence of variations in the genomes of members of the same species. These variations are primarily caused by three factors: mutation, genetic recombination, and gene flow in the population. The term “mutation” is used to describe changes in the DNA sequences of organisms. Gene flow, on the other hand, refers to the transfer of genetic material between populations. Finally, genetic combination, which is formed through sexual reproduction, encompasses the formation of new gene combinations.

How are genetic mutations caused?

Mutations are changes in the nucleotide sequence of a short region of a genome, often resulting from errors in DNA replication or the damaging effects of mutagens. All cells possess DNA-repair enzymes that attempt to minimize mutations, working either pre-replicatively to search for nucleotides with unusual structures and replace them before replication occurs, or post-replicatively to check newly synthesized DNA for errors and correct them. Mutations may be considered a deficiency in DNA repair.

Recombination results in a restructuring of part of a genome, such as exchange of segments of homologous chromosomes during meiosis or transposition of a mobile element within or between chromosomes. Other events, such as mating-type switching in yeast and construction of immunoglobulin genes, are also the results of recombination. Recombination is a cellular process carried out and regulated by enzymes and other proteins, similar to other cellular processes involving DNA, such as transcription and replication.

What are the causes of mutation in plant breeding?

Ionizing radiation is a widely used physical agent to induce hereditary changes in plants, allowing for the creation of heritable mutations. Natural methods to induce genetic diversity have been used for millennia to improve food crops, but the frequency of mutations is insufficient to meet current needs. Mutation induction and mutation detection have been crucial tools for plant breeders for over 70 years to increase genetic diversity and derive new mutant lines with improved characteristics.

The International Atomic Energy Agency (IAEA) collaborates with the Food and Agriculture Organization (FAO) to develop and adopt nuclear-based technologies to optimize mutation induction practices, aiming to intensify crop production and preserve natural resources.

What are the two main sources of genetic variation?

Natural selection involves mutations and recombination of genes through sexual reproduction. Most mutations do not affect individual reproductive fitness, but about 10% may be phenotypically expressed and acted upon by selection. Mutation rates per gene are generally low, but the number of genes in organisms, estimated to be between 30, 000-60, 000 in humans, can vary by 500-fold among genes within species and up to 100, 000-fold between species. As a result, all offspring likely carry at least one new allele in their genome.

What is the creation of variation in plant breeding?

Plant mutation breeding, also known as variation breeding, is a method that uses physical radiation or chemical means to induce spontaneous genetic variation in plants to develop new crop varieties. Mutation is a natural process that occurs spontaneously and slowly over generations in people, plants, animals, and all living beings. It involves altering DNA, leading to the development of changes within the organism. Mutation can be sped up by chemical or physical methods, such as radiation (irradiation), to achieve characteristics useful in agriculture.

Irradiation can produce plant varieties with improved qualities, such as higher yields, shorter cultivation times, and resistance to diseases, pests, and climate change effects. Cultivation and popularization of these plant varieties help make global food production more stable and address the needs of farmers, particularly in developing countries and regions most vulnerable to climate change impacts.

Radiation-bred plant varieties are equally safe as those developed through conventional or marker assisted breeding, allowing plants to be bred for many generations without damage or becoming radioactive.

What are the components of genetic variance in plant breeding?

This chapter discusses genetic components of variability, which can be categorized into additive variance (VA), dominance variance (VD), and epistatic variance (VI). It delves into the sources of phenotypic variation, whether genetic or environmental, and how they contribute to the heritability of selected traits. The chapter also discusses the derivation of variance components, covariance, the relationship among them, and the role of epistasis.

It also discusses the impact of allele frequencies on genetic components of genotypic variability, the limitations of genetic variability estimates, and the possibility of additive genetic variance from genes with any degree of dominance or epistasis.

Is a genetic variant the same as a mutation?

Gene variants are permanent changes in the DNA sequence that make up a gene, which were previously known as gene mutations. These variants can affect one or more DNA building blocks in a gene and can be inherited from a parent or occur during a person’s lifetime. Inherited variants, also known as germline variants, are passed from parent to child and are present in virtually every cell in the body. They are present in the parent’s egg or sperm cells, which contain DNA from both parents.

Non-inherited variants, on the other hand, occur at some point in a person’s life and are present only in certain cells, not in every cell in the body. They are often referred to as somatic variants and cannot be passed to the next generation. Non-inherited variants can be caused by environmental factors or errors made during cell division.

What are 4 causes of genetic variation?

Genetic variation refers to the variation in the genetic makeup of individuals within a population, resulting from mutations, random mating, random fertilization, and recombination during meiosis. It is a crucial force in evolution, allowing natural selection to increase or decrease the frequency of existing alleles. Genetic variation is advantageous to a population as it allows some individuals to adapt to the environment while maintaining the survival of the population. It is essential for understanding the ways genetic variance affects population evolution.