Plant Breeding- Definition, Goals, Types, Steps, And Factor Affecting

Plant breeding definition: It is a form of agricultural science whose primary focus is to modify plants' qualities to fulfil certain objectives. A controlled pollination and selection process allows breeders to change the gene pool of plants such that it allows the development of particular genetic characteristics, including high yield, quality, disease and pest resistance, and the ability to withstand unfavourable environmental conditions. Plant breeding is a topic of Strategies For Enhancement In Food Production in Biology.

Latest: NEET 2024 Paper Analysis and Answer Key 

Don't Miss: Most scoring concepts for NEET | NEET papers with solutions

New: NEET Syllabus 2025 for Physics, Chemistry, Biology

NEET Important PYQ & Solutions: Physics | Chemistry | Biology | NEET PYQ's (2015-24)

This Story also Contains

1. Objectives of Plant Breeding
2. Plant Breeding Techniques
3. Types of Plant Breeding
4. Conventional breeding methods
5. Steps in Plant Breeding
6. Factors Affecting Plant Breeding
7. Role of Plant Breeding
8. Challenges in Plant Breeding

What is Plant Breeding?

It involves the identification of the parent plants with desired traits and, successively, the interbreeding of the selected plants in such a way that the resulting offspring have the desired characteristics of both parents. In the subsequent generation, selection and evaluation procedures are applied to select organisms that enhance the stabilisation or improvement of such characteristics.

Plant breeding is a cross-section of genetics, genomics, and biotechnology designed to generate improved plant cultivars that meet the challenges of agriculture today and into the future.

As the centre of cropping system improvement, plant breeding has the responsibility of increasing crop varieties to feed the world’s increasing population and meet the demand for food, feed, fibre, and fuel. Plant breeding makes crops produce more, hence improving the productivity and profitability of agriculture, food security and economic development. Furthermore, these improved varieties that provide disease and pest tolerance, mean that there is less reliance on chemicals in farming, and environmental effects are minimised. This is a key aspect because it enables plant breeders to fully explore the variations in genes so that a desirable trait in a gene may be looked for in a crop plant and introduced in the same way, hence making genetic diversity a very vital tool in plant breeding.

Also read:

• MCQ Practice on Plant Breeding

• Animal Husbandry

• Strategies For Enhancement In Food Production

• Agricultural Implements

Objectives of Plant Breeding

The various objectives of Plant Breeding are listed below-

Increased Yield

More yield potential is one of the plant breeding objectives that strives to achieve existing as well as new crop varieties. By genetically altering crops and focusing on bringing new varieties containing better and improved traits like; bigger fruits, stronger stems, and more efficiency at utilising light energy, the breeders enhance crop production enough to feed the increasing population and for the production of other agricultural products.

Disease Resistance

Crop breeders work to produce plant materials that are more resistant to diseases transmitted by pathogens like fungi, bacteria, viruses and nematodes. Herd immunity decreases yields’ susceptibility to disease and the application of hazardous chemicals to fight pests, thus encouraging sustainable agricultural practices.

Abiotic Stress Tolerance

A second major goal in plant breeding is to improve plant resilience to abiotic stresses, including water availability, heat, salinity, and low/high temperatures. The breeders pick useful traits that will make the plants resistant to harsh environmental forces, hence helping the farmers to improve their yields.

Improved Quality

The quality traits of the crops are also targeted by plant breeding initiatives through enhancement of taste, texture, nutritive values as well as its shelf qualities. Regarding breeding aims, breeders select for such qualities as flavour, nutrient content, shelf life, and processing suitability and thus improve consumer preferences and supply chain positioning.

Adaptation to Climate Change

As climate change continues to worsen, its effects on agriculture are felt; hence, plant breeders are working towards generating improved strains of crops for the changing climate. This entails the selection of desirable characteristics, including heat check, drought, salinity, water use, heat stress tolerance, and the ability to cope with changing climate and weather patterns to support food production.

Reduced Input Requirements

The technique of plant breeding is very important in reducing the inputs for crop production, for instance, water, fertilizers, and chemicals. Through the release of varieties that have higher NUE, WUE, and PR, the breeders are helping the farmers conserve resources, minimise costs, and promote sustainable farming methods.

Plant Breeding Techniques

The means of selection by breeding is achieved through controlled crosses between plants carrying the desired traits to obtain offspring plants with superior features. These techniques of Plant Breeding involve the use of natural genetic variation and conventional plant breeding systems to produce new plant types.

Mass Selection

Plant propagation is done through the choosing of individual plants from the population and planting them based on some desirable characteristics like yield, disease resistance quality, etc., which is called mass selection. This method is quite simple and often employed to give quick responses in selection programmes to improve populations.

Pure Line Selection

Pure-line selection is a method of choosing closely related plants in an attempt to treat them as a population so that plants similar to the selected ones can be produced after several generations. A process of continual asexual reproduction or accidental self-fertilisation can determine the fixity of the valuable characters in a variety.

Backcrossing

In the backcrossing technique, this is achieved by crossing the desirable but genetically complex plant, which is referred to as the recurrent parent, with the genetically simple plant, referred to as the donor parent from which the desirable genes are derived, and then successively crossing the progeny of the first cross back to the recurrent parent. This method is useful when one is looking to transfer specific characteristics from the donor parent to the progeny while keeping the general genotype of the recurrent parent.

Hybridisation

Hybridisation in plant breeding is the process of uniting two plants that belong to different genetic varieties so that the offspring will have the favourite characteristics that are from the parent stock. They tend to show such phenomena as heterosis or hybrid vigour and, therefore, possess higher productivity than that of the initial rows.

Cross-Pollination

The process of cross-pollination is initiated whereby pollen produced from one plant germinates on the stigma of another plant, with resultant seed formation from both parents. This method is applied especially to crops with open flowers where they have undergone pollination.

Inbreeding

Inbreeding is the process of breeding organisms in a population that has similar genes and alleles, to give their offspring homozygous genotypes. These consequences are stipulated by the fact that inbreeding can enhance such favourable phenotypic characteristics as resistance to diseases and better adaptation to environmental conditions; at the same time, it can lead to inbreeding depression because of the intense accumulation of non-adaptive genes.

Mutation Breeding

Mutation breeding is a process of deliberately arising variations in plant genomes using physical and chemical treatments known as mutagens. The mutations with the preferred qualities are the next ones selected and bred for further testing as well as selective breeding.

Induced Mutations

Induced mutations are obtained after mutagens like radiation or chemicals have been used to influence change within the plants’ DNA sequences. These mutations can develop new characteristics that may be desirable for crops and can be availed for making improvements.

Selection of Mutants

Mutations are followed by the screening of plants for the desirable genes, possibly from stably integrated mutagen-induced changes and the selection of plants with wanted phenotypes and genotypes. These selected mutants are then bred to an elite variety to introduce those desirable traits to breeding programmes

Genetic Engineering

Genetic alteration is a direct interference with an organism’s DNA to add or delete some characters or features. This approach enables breeders to introduce or knock out desired genes, meaning it makes targeting crop performances possible.

Marker-Assisted Selection (MAS)

MAS is the process of selecting plants with particular desirable characteristics by making use of molecular markers that are connected to the desired characteristic. It also helps in the selection of improved genotypes since it involves a faster method of selecting the best parents, thereby increasing the rate of breeding

Transgenic Approaches

Genetic engineering entails the insertion of beneficial genes into plants for desired traits like insect resistance, herbicide tolerance, or good nutritional quality. Examples of transgenic plants include plants that are produced through gene cloning and plant transformation.

Genome Editing Techniques

It is easier to manipulate plant genomes as new biotechnology tools like genome editing make it possible to target specific DNA sequences for editing. They make it possible to increase, decrease, or change specific genes and expand the gene technology possibilities with higher specificity and effectiveness for plants. These techniques help improve plant genetics.

Types of Plant Breeding

One of the types of plant breeding methods is Conventional breeding, and the other is Modern biotechnological approaches.

Conventional breeding methods

The breeding methods are-

Mass selection

Mass selection is the process of choosing individual plants from a given population of plants and then increasing the number of those plants based on the traits that are wanted, such as yield, disease tolerance, or quality. SIE is a simple method and is initially applied in breeding programmes to make rapid progress in populations. Settlement of choice is based on the visual observation of plants and the selection of those that possess the required characteristics; thus, the process of compiling the necessary genes in subsequent generations takes place.

Pure line selection

Pure line selection tends to create populations that are genetically pure by the identification of pure stock plants bearing similar traits for many generations. This is done through the process of selling or by vegetative means to bring about repeatability in the particular commendable traits of the population. This method is especially applicable for traits determined by only a few genes and is useful for improving the generation of uniformly high-yielding varieties.

Backcrossing

Backcrossing is a technique in which, a desirable genetically unrelated plant, known as the 'recombinant parent’ is crossbred with the ‘donor parent’ which is a high-yielding and genetically uniform variety, and the resulting hybrid progeny is repeatedly crossed back with the donor parent. This method aids in the transfer of certain desirable characters from the donor parent to the recurrent parent’s genotypic background. Backcrossing is often applied when the objective is to transfer a specific gene, such as disease resistance or any other desirable gene, into the elite line along with its desirable qualities.

Steps in Plant Breeding

The following steps summarise plant breeding and crop improvement techniques.

Objective Identification

The first requirement to be established in plant breeding is the breeding goals, which may involve yield, pest and disease control, quality attributes, and maturity or early or late maturity among other factors. In some contexts, breeders evaluate the interests of farmers, consumers’ demands, and some factors of breeders to identify specific breeding objectives.

Selection of Parental Plants

Following the description of breeding objectives, the breeders then choose the appropriate parental plants that will act as the source of variation. The source of the parental plants may be from cultivars, breeding lines, or wild germplasm collections. It is important because it affects the choice of genetic variation and relevant abilities of the offspring; therefore, the choice of parents is vital.

Cross-pollination or Hybridisation

Here, the breeders ensure that pollen from the stamen of one plant's female sex organ is placed on the stigma of the pistil of another plant, either through self-pollination or by cross-pollination. The process, referred to as cross-pollination or hybridisation enables the development of different progeny with features extracted from the selected parents.

Selection and Evaluation of Progeny

Progeny development is also an important stage, and by the time of its completion, breeders analyze the progeny for the presence of desirable features. This may include the cultivation of numerous plants or the Multiplication of a large number of plants and the choice of one with the best phenotypes that have been identified through certain characteristics. ? Selection may be carried out at different growth and development phases of plants, right from germination to flowering, to get the best plant type.

Testing and Release of New Cultivars

Offspring go through a series of tests, which are carried out under field conditions, to establish their performance in different environments and management practices. Technological advancement enhances the recognition of desired genes by breeders through yield, disease resistance, quality, and adaptability to release new cultivars. After the elimination of some characteristics and achieving level criteria, new cultivars are released and used by farmers for production and dissemination.

The above points summarise steps in plant breeding and the important crop improvement techniques.

Factors Affecting Plant Breeding

Various factors influence plant breeding:-

Environmental Factors

Some factors affect plant breeding, which include temperature, rainfall, soil type, and photoperiod. While growing crops, the various environmental factors that suit the plant’s growth and development must be taken into account by the breeders when choosing the right crop to develop into a new variety.

Genetic factors

Populations’ genetic variation affects the performance of cultivar development programmes. Breeders attempt to control and use genetic differences regarding characteristics such as yield, disease tolerance, and quality directly relating to nutrients. The degree of relationship within breeds can have an impact on breeding practices by explaining the mode of inheritance of certain traits.

Breeding Goals and Objectives.

Breeding aims and targets are used to determine the choice of parents, the techniques of plant breeding, and the assessment parameters in plant breeding. Therefore, the interests of breeders are not fixed but tend to shift based on market requirements, agricultural production, and climate adversities, pointing towards the future objectives of breeding.

Technological Advancements

Genetics, genomics, and biotechnology have preceded a transformation in the breeding strategy of plants. Techniques like molecular markers, genetic transformation, and genome editing help the breeders enhance the new breed of improved crop varieties with accuracy and at a faster rate. These technologies increase the rate, precision, and efficiency of breeding, which results in the early release of new cultivars.

Role of Plant Breeding

Various roles of plant breeding include:

Improvement of Crop Yield and Quality

The objectives of plant breeding include improving the rates of crop production and also the quality in terms of taste, texture as well as nutritional value. These enhanced types can enable greater food production and better quality produce that help to enhance yields and meet producers’ as well as consumers’ expectations.

Development of Disease-Resistant Varieties

One of the essential areas of plant breeding is the improvement of crop resistance to pathogens, including fungi, bacteria, viruses, and nematodes. It is effective because disease-resistant varieties help in cutting losses due to diseases and, consequently, reduce the need for chemical pesticides, thus embracing sustainable farming and protection of the environment.

Adaptation to Environmental Stresses (Drought, Salinity, Etc.).

Breeding makes crops resistant to biotic stresses like drought, salinity, heat, cold, waterlogging, and other adversities of nature. These stress-tolerant varieties lead to production and income security, helping farmers adapt to poor production conditions and vice versa.

Nutritional Enhancement of Crops.

There is an impact of plant breeding on food security as well. Plant breeding activities include enhancement of crop quality to help overcome malnutrition and other dietary deficit problems. Enhanced nutrients Biofortification is useful and delivers health benefits to vulnerable people to allow them to fight micronutrient deficiencies. This shows the impact of plant breeding on food security.

Development Of Biofortified Crops.

By using plant breeding, biofortification focuses on improving the nutritional quality of crops in specific ways, usually relating to vitamins and minerals. These crops relieve the scarcity of some nutrients in human diets, leading to better health and nutrition. Biofortification interventions involve enhancing the levels of micronutrients in foods that are often consumed in large quantities, including rice, wheat, maize, beans, and the like, through the enhancement of their iron, zinc, vitamin A, and vitamin C content.

Economic Benefits For Farmers And Agricultural Industry

Technological advancement in crop breeds raises productivity in agriculture and the fortunes of farmers, hence enhancing the economy and encouraging development in rural areas. Genetic improvement technologies propel change and efficiency in the agricultural value chain, sustaining the population’s income.

Conservation of Plant Genetic Resources

Plant breeding programmes are also helpful and involved in the conservation and use of plant genetic resources through germplasm holdings. Genetic differences help crops be more interpretable and immune to diseases, viruses, and climate change, among other disasters.

Sustainable Agriculture Practices

Plant breeding enhances sustainable agriculture practices by improving crop types that require fewer inputs and are resistant to diseases and environmental stresses. Sustainable varieties reduce the use of chemicals, rationalise the use of natural resources, and reduce adverse impacts.

Challenges in Plant Breeding

Challenges in plant breeding include:-

Genetic Constraints

The genetic variation among the plant populations may sometimes prove deleterious to the breeding programmes, especially where simple inheritance is not followed, including polygenic traits. To realise the desired quality improvement in crop varieties, breeders are faced with various genetic barriers.

Time and Resources

The process of plant breeding is rather lengthy and capital-intensive and very much depends on research funds, facilities, and personnel. Unfortunately, time is always scarce, and with limited resources and funds, breeding efforts can easily be sluggish and slowed down significantly in their attempts to produce new cultivars.

Regulatory and Ethical Considerations

Plant breeding activities are associated with specific rules and an ethical code of conduct about the release and market introduction of GMOs. The legality and ethicality of breeding activities create complications and expenses.

Public Acceptance of Genetically Modified Organisms (GMOs)

Currently, people have different attitudes towards the use of GMOs, This is regarding issues of safety, environmental effects, and ethical issues. Based on the arguments avowed in this piece of work, breeders and policymakers have a challenge in the process of engaging the public on genetically modified crops.

Intellectual Property Rights Issues

Concerning patents and plant variety rights, there are IPR paradoxes of plant breeding that hinder access to genetic resources and technologies. Synchronization of IPR regimes regarding breeders, farmers, as well as the public is a delicate task.

Also Read: