Agricultural Biotechnology: Definition

What is Agricultural Biotechnology?

Agricultural biotechnology is the use of different scientific techniques to modify plants and animals. The undesirable characteristics like susceptibility to diseases and low productivity are bred out. If there is a particular trait that the plant or animal can benefit from, it can be bred in by using a gene that contains the characteristic.

Biotechnology has especially been beneficial in improving agricultural productivity and increasing the resistance of plants to diseases. Scientists do this by studying the DNA. They first identify the gene that would be beneficial to the plant or animal, then work with the characteristics conferred in a precise and exact manner to achieve the desired outcome.

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 How Agricultural Biotechnology is Used

1. Genetic Engineering

Genetic engineering, also referred to as genetic improvement or modification, is the movement of a gene from one organism to another. This process allows for the transfer of a useful characteristic into an organism by inserting it with a gene containing the particular trait. In crops, genetic engineering has been used to increase productivity and resistance to weeds and harsh weather conditions.

2. Molecular Markers

Genetic engineering, also referred to as genetic improvement or modification, is the movement of a gene from one organism to another. This process allows for the transfer of a useful characteristic into an organism by inserting it with a gene containing the particular trait. In crops, genetic engineering has been used to increase productivity and resistance to weeds and harsh weather conditions.

3. Vaccines

Biotechnology is used for making vaccines for both animals and human beings. These vaccines are better than the traditional ones because they are cheaper, safer, and can survive warmer tropical temperatures. Vaccines to prevent new infections have also been developed using biotechnology.

4. Genomics

A genome is an entire set of chromosomes found in the DNA, and through the study of genomes and genetic mechanisms, breakthroughs have been made in biotechnology. Through genomics, the structure, function, location, and impact of a particular gene and genome are identified. This makes it easy to determine the characteristics that will be transferred to another organism and the exact results of the transfer of the gene.

5. Tissue Culture

This technique is used to produce a plant that is free from undesirable characteristics, which are, mostly, diseases. A disease-free plant part is used to generate types that are disease-free. The different types of plants in which tissue culture works include bananas, avocados, mangoes, coffee, and papaya, among others.

How have agricultural technologies evolved over time

For about 10000 years, humans have attempted to improve plant characteristics by selecting and breeding individuals with desired characteristics. As a consequence, modern plants now differ substantially from their ancestors.

1. Understanding, characterizing and managing genetic resources

Farmers and pastoralists have manipulated the genetic make-up of plants and animals since agriculture began more than 10 000 years ago. Farmers managed the process of domestication over millennia, through many cycles of selection of the best adapted individuals. This exploitation of the natural variation in biological organisms has given us the crops, plantation trees, farm animals and farmed fish of today, which often differ radically from their early ancestors.

The aim of modern breeders is the same as that of early farmers – to produce superior crops or animals. Conventional breeding, relying on the application of classic genetic principles based on the phenotype or physical characteristics of the organism concerned, has been very successful in introducing desirable traits into crop cultivars or livestock breeds from domesticated or wild relatives or mutants. In a conventional cross, whereby each parent donates half the genetic make-up of the progeny, undesirable traits may be passed on along with the desirable ones, and these undesirable traits may then have to be eliminated through successive generations of breeding. With each generation, the progeny must be tested for its growth characteristics as well as its nutritional and processing traits. Many generations may be required before the desired combination of traits is found, and time lags may be very long, especially for perennial crops such as trees and some species of livestock. Such phenotype-based selection is thus a slow, demanding process and is expensive in terms of both time and money. Biotechnology can make the application of conventional breeding methods more efficient.

Induced mutation-assisted breeding

Spontaneous mutations are the “natural” motor of evolution, and the resource into which breeders tap to domesticate crops and to “create” better varieties. Without mutations, there would be no rice, or maize or any other crop.

Starting in the 1970s, the International Atomic Energy Agency (IAEA) and FAO sponsored research on mutation induction to enhance genetic improvement of food and industrial crops for breeding new improved varieties. Induced mutations are brought about by treating plant parts with chemical or physical mutagens and then selecting for desirable changes – in effect, to mimic spontaneous mutations and artificially broaden genetic diversity. The precise nature of the mutations induced has generally not been a concern, irrespective of whether the mutant lines were used directly or as sources of new variation in cross-breeding programmes.

Induced mutation to assist breeding has resulted in the introduction of new varieties of many crops such as rice, wheat, barley, apples, citrus, sugar cane and banana (the FAO/IAEA Mutant Varieties Database lists more than 2 300 officially released varieties). The application of mutation induction to crop breeding has translated into a tremendous economic impact on agriculture and food production that is currently valued in billions of US dollars and millions of hectares of cultivated land. Recently, mutation techniques have undergone a renaissance, expanding beyond their direct use in breeding into novel applications such as gene discovery and reverse genetics.

History of Agricultural Biotechnology

History of Agricultural Biotechnology: How Crop Development has Evolved

Have you ever wondered where our agricultural crops come from? And what were they like thousands of years ago, or hundreds of years ago? Our food crops today are in fact very different from the original wild plants from which they were derived.

About 10,000 years BC, people harvested their food from the natural biological diversity that surrounded them, and eventually domesticated crops and animals. During the process of domestication, people began to select better plant materials for propagation and animals for breeding, initially unwittingly, but ultimately with the intention of developing improved food crops and livestock. Over thousands of years, farmers selected for desirable traits in crops, and thus improved the plants for agricultural purposes. Desirable traits included crop varieties (also known as cultivars, from “cultivated varieties”) with shortened growing seasons, increased resistance to diseases and pests, larger seeds and fruits, nutritional content, shelf life, and better adaptation to diverse ecological conditions under which crops were grown.

Over the centuries, agricultural technology developed a broad spectrum of options for food, feed, and fibre production. In many ways, technology reduces the amount of time we dedicate to basic activities like food production, and makes our lives easier and more enjoyable. Everyone is familiar with how transportation has changed over time to be more efficient and safer. Agriculture has also undergone tremendous changes, many of which have made food and fibre production more efficient and safer. For example, in 1870, the total population of the USA was 38,558,371 and 53% of this population was involved in farming; in 2000, the total population was 275,000,000 and only 1.8% of the population was involved in farming. There are negative aspects to having so few members of society involved in agriculture, but this serves to illustrate how technological developments have reduced the need for basic farm labour.

This article concentrates on how scientific discoveries and technological developments have allowed us to improve crop development in agriculture. Most people do not realize that among early agriculture developments, really at the genesis of agricultural technology, the ancient Egyptians made wine and made rising dough for bread, using fermentation. A significant event in the development of agriculture occurred in 1492 with the introduction of corn, native to the Americas, to the rest of the world, and European growers adapted the plant to their unique growing conditions. At this stage of history, crops were being transported around the world and grown under a diversity of conditions.

Agriculturalists started conducting selective breeding of crops before having a thorough understanding of the basis of genetics. Gregor Mendel's discoveries explaining how traits pass from parents to offspring shed new light on the matter. Mendel's work showed that genes separate during the formation of gametes, and unite randomly during fertilization; he also showed that genes are transmitted independently of one another to offspring. This understanding of the way that plants and animals acquire traits from parents created the potential for people to selectively breed crops and livestock. Gregor Mendel's discovery revolutionized agriculture by launching the development of selective cross-breeding with a comprehensive understanding of the underlying mechanisms of inheritance.

Selective Cross Breeding

This article concentrates on how scientific discoveries and technological developments have allowed us to improve crop development in agriculture. Most people do not realize that among early agriculture developments, really at the genesis of agricultural technology, the ancient Egyptians made wine and made rising dough for bread, using fermentation. A significant event in the development of agriculture occurred in 1492 with the introduction of corn, native to the Americas, to the rest of the world, and European growers adapted the plant to their unique growing conditions. At this stage of history, crops were being transported around the world and grown under a diversity of conditions.

Agriculturalists started conducting selective breeding of crops before having a thorough understanding of the basis of genetics. Gregor Mendel's discoveries explaining how traits pass from parents to offspring shed new light on the matter. Mendel's work showed that genes separate during the formation of gametes, and unite randomly during fertilization; he also showed that genes are transmitted independently of one another to offspring. This understanding of the way that plants and animals acquire traits from parents created the potential for people to selectively breed crops and livestock. Gregor Mendel's discovery revolutionized agriculture by launching the development of selective cross-breeding with a comprehensive understanding of the underlying mechanisms of inheritance.

Classical Breeding with Induced Mutation

Mutations are changes in the genetic makeup of a plant. Mutations occur naturally and sometimes result in the development of new beneficial traits. In 1940, plant breeders learned that they could make mutations happen faster with a process called mutagenesis. Radiation or chemicals are used to change the plant's DNA, the basic molecular system of all organisms' genetic material. The goal is to cause changes in the sequence of the base pairs of DNA, which provide biochemical instructions for the development of plants. Resultant plants may possess new and desirable characteristics through this modification of their genetic material. During this process, plant breeders must grow and evaluate each plant from each seed produced.

More than 2,500 plant varieties (including rice, wheat, grapefruit, lettuce, and many fruits) have been developed using radiation mutagenesis (FAO/IAEA, 2008). Induced mutation breeding was widely used in the United States during the 1970s, but today few varieties are produced using this technique. As our understanding of genetics developed, so new technologies for plant variety development arose. Examples of these that are used today include genetic marker assisted breeding, where molecular markers associated with specific traits could be used to direct breeding programs, and genetic engineering. Some significant steps leading to the current state of the art are explained below.

1. Discovery by Watson and Crick: structure of DNA, 1953: Another milestone in the development of understanding of genetics and how genes function, was the discovery of the structure of DNA (the basis of genes), and how DNA works. Two scientists, James Watson and Francis Crick made this discovery (Pray 2008), considered to be one of the most significant scientific works in biology, largely through synthesis of the work of other scientists. Their work contributed significantly to understanding what genes were.

2. Discovering genes that move (transposons): Transposons are sections of DNA-genes-that move from one location to another on a chromosome. Transposons have been referred to as “jumping genes”, genes that are able to move around. Interestingly, transposons may be manipulated to alter the DNA inside living organisms. Barbara McClintock (1950) discovered an interesting effect of transposons. She was able to show how the changes in DNA caused by transposons affected the colour of maize kernels.

3. Tissue culture and plant regeneration: Another significant development in technology that was important for plant breeding was the development of micropropagation techniques, known as tissue culture (Thorpe 2007). Tissue culture permits researchers to clone plant material by excising small amounts of tissue from plants of interest, and then inducing growth of the tissue on media, to ultimately form a new plant. This new plant carries the entire genetic information of the donor plant. Exact copies of a desired plant could thus be produced without depending on pollinators, the need for seeds, and this could all be done quickly.

4. Embryo rescue: Often when distantly related plant species are hybridized are crossed, the embryos formed following fertilization will be aborted. The development of embryo rescue technology permitted crop breeders to make crosses among distantly related varieties, and then to save the resulting embryos and then grow them into whole plants through tissue culture.

5. Protoplast fusion: Protoplasts are cells that have lost their cell walls. The cell wall can be removed either by mechanical means, or by the action of enzymes. They are left with only a cell membrane surrounding the cell. Protoplasts can be manipulated in many ways that can be used in plant breeding. This includes producing hybrid cells (by means of cell fusion) and using protoplasts to introduce new genes into plant cells, which can then be grown using tissue culture techniques (Thorpe 2007).

6. Genetic engineering: Building on the above discoveries into the 1980s, advances in the field of molecular biology provided scientists with the potential to purposefully transfer DNA between organisms, whether closely or distantly related. This set the stage for potentially extremely beneficial advancement in crop breeding, but has also been very controversial.

 Advantages of Agricultural Biotechnology

Biotechnology has been beneficial in many ways. First, stabilized plants that have higher yields have been produced successfully. The resistance of these plants to pests, diseases and abiotic factors such as rainfall has played a major role in increasing the yields.

Animal feeds are being improved by biotechnology to increase their nutrient intake and reduce environmental wastes.

Another advantage of biotechnology is that it has led to the development of better vaccines that don't necessarily have to be stored in very cold temperatures. Penicillin, one of the most important components of antibiotics, was produced through biotechnology.