1. Application of biotechnology in textile industry
Part 1 Harvesting of Bt cotton
Prof. R.B.Chavan
Department of textile technology
Indian Institute of Technology
Hauz-khas, New Delhi 10016
E.Mail rbchavan@hotmail.com
Introduction
Biotechnology is defined as industrial exploitation of biological systems or processes.
It includes any technique that uses living organisms or part of it to make or modify
products, to improve plants or animals or to develop microorganisms for specific uses.
Individual characteristics of living organisms, such as the colour of petals, are determined
by their genes. These characteristics, or traits, are inherited from generation to generation.
Genetic modification involves copying the genes which govern a particular characteristic.
from one organism, and transferring them to another. With conventional breeding, traits
can only be transferred between plants or animals of the same or closely related species.
Genetic modification enables traits to be transferred between different species. The rapid
developments in the field of genetic engineering have given a new impetus to
biotechnology. With an improved understanding of how different genes are responsible
for the various characteristics and properties of a living organism, techniques have been
developed for isolating these active components (in particular, the DNA which carries the
genetic code) and manipulating them outside of the cell. The next step has been to
introduce fragments of DNA obtained from one organism into another, thereby
transferring some of the properties and capabilities of the first to the second.
Discoveries in Biotechnology allow for certain key crops to have their own protection
against insects and disease. These crops can, therefore, be grown using less pesticides.
India loses tremendous amounts of crops to pests and diseases. For example, India is the
3rd largest producer of cotton in the world. While cotton occupies only 5% of the
cultivated area, it accounts for almost half the pesticides sold in India. This is due to the
devastating pest the cotton bollworm. One of the plants that are undergoing evaluation in
India is Bt cotton (Bacillus thurigiensis) that offers protection against this pathogen and

2. will drastically reduce the use of pesticides. In the future, some applications of
Biotechnology will be used to make materials such as fibers for clothes from “renewable”
resources like corn. Other applications may help reduce our dependence on oil and
natural gas and could reduce water and energy use by as much as 50 percent.
Some of the technologies relevant to textile industry based on biotechnological
applications are
1. Harvesting of Bt cotton
2. Natural polyester in the form of poly hydroxy butyrate to grow within central
hollow channel of the cotton fibre.
3. Biodegradable polyester from corn
4. Biosynthesis of indigo and other colours
5. Monochlonal anti bodies for the identification of branded products such as
denim.
6. DNA probes
7. Biosensors
8. Chemical processing of textiles
9. Aftercare of garments
10. Effluent treatment. etc.
In the present article the harvesting of Bt cotton in India is discussed
Bt Cotton
Cotton crop is easily attacked by various types of pests causing extensive damage. Some
of the pests which cause major damge to cotton crop are
Cotton bollworm, Tobacco budworm, loopers, fall armyworm, beet armyworm etc. These
worms are shown pictorially

3. Cotton bollworm Tobacco budworm
Loopers Fall armyworm
Beet armyworm
Bollworm damage of non-Bt cotton

4. Intensive use of pesticides is essential to protect cotton crop. Almost 50% of pesticide
consumption is accounted for cotton. Over the past 40 years; many pests have developed
resistance to pesticides. We have a year. The
So far, the only successful approach to engineering crops for insect tolerance has been the
addition of Bt toxin (Bacillus thurigiensis), a family of toxins originally derived from
soil bacteria. The Bt toxin contained by the Bt crops is no different from other chemical
pesticides, but causes much less damage to the environment. These toxins are effective
against a variety of economically important crop pests but pose no hazard to non-target
organisms like mammals and fish. Three Bt crops are now commercially available:
cotton, corn, and potato.
The Bt gene was isolated and transferred from a bacterium bacillus thurigiensis to
American cotton. The American cotton was subsequently crossed with Indian cotton to
introduce the gene into native varieties.
The Bt cotton variety contains a foreign gene obtained from bacillus thuringiensis. This
bacterial gene, introduced genetically into the cotton seeds, protects the plants from
bollworms, a major pest of cotton. The worm feeding on the leaves of a BT cotton plant
becomes lethargic and sleepy, thereby causing less damage to the plant.Thus
Bt cotton has been genetically modified by the insertion of one or more genes from a
common soil bacterium, Bacillus thuringiensis
In 1996, Bollgard cotton (a Trademark of Monsanto) was the first Bt cotton to be
marketed in the United States. The original Bollgard cotton produces a toxin called
which has excellent activity on tobacco budworm and pink bollworm. These two insects
are extremely important caterpillar pests of cotton, and both are difficult and expensive to
control with traditional insecticides. Bollgard toxin also has moderate activity on
bollworm and to a lesser extent on loopers, fall armyworms and beet armyworms.
Bollgard II was introduced in 2003, representing the next generation of Bt cottons.
Bollgard II contains a second gene from the Bt bacteria which encodes the production of
Cry 2Ab. WideStrike (a Trademark of DowAgrosciences) was registered for use in
2004. Like Bollgard II, WideStrike cotton expresses two Bt toxins (Cry1Ac and Cry1F).
Both Bollgard II and WideStrike have better activity on a wider range of caterpillar pests

5. than the original Bollgard technology. Bt cottons from other companies are currently
under development but have not been commercially introduced.
How Bt cotton affects insect pest management
Bt cotton eliminates the need to treat for infestations of tobacco budworm or pink
bollworms. Prior to bloom, the need to treat for bollworm is greatly reduced. However,
the level of bollworm control provided by Bollgard cotton may not be sufficient once
cotton has begun to bloom. Bollgard may also suppress the development of damaging
populations of other caterpillar pest, but insecticidal sprays on Bollgard cotton for control
of bollworm, loopers, and beet and fall armyworm are sometimes needed. Supplemental
insecticides sprays for bollworm, loopers and armyworms will be less likely on Bollgard
II and WideStrike cottons.
Resistance and resistance management
It seems likely that some cotton pests could develop resistance to Bt crops if they are
extensively used. Insects such as the tobacco budworm are well known for their ability to
develop resistance to many insecticides, including Bt toxins. Because of this, there are
restrictions associated with the use of Bt cotton that are intended to prevent or delay the
development of resistance. The primary resistance management strategy is the
mandatory planting of a non-Bt cotton Refuge. The plantation of non-Bt cotton close to
or adjacent to Bt cotton fields will provide a source of susceptible moths for mating with
resistant moths that survive in Bt cotton The refuge serves as a source of susceptible
insects that would potentially breed with any resistant insects generated in Bt cotton
fields. The offspring of this mating would be susceptible to Bt toxins
A second resistance management tactic would be the introduction of Bt crops that
produce two or more relatively dissimilar toxins. Presumably, it is less likely that any
one insect will be simultaneously resistant to more than one toxin. It is expected that
Bollgard II, WideStrike and Bt cottons from other companies will eventually replace the
original Bollgard technology in 5-6 years.
Is Bt cotton safe?
Bt toxins are highly specific. The toxins produced by Bt cotton and corn are toxic to a
select number of arthropod species. Because cotton is primarily a fiber crop, the

6. contamination of food with toxins from cotton is highly unlikely. However, extensive
testing indicates a very low public health risk from the use, including ingestion, of food
products that utilize currently-available Bt crops.
Negative impacts on non-target arthropods are potential concerns resulting from the use
of Bt crops. Concerns were raised because corn pollen, containing Bt toxins, could be
blown onto plants which serve as hosts to monarchs, swallowtails, and other butterflies.
This is not a minor issue with cotton because, unlike corn, it is not wind pollinated. It
should also be considered that Bt crops often reduce the use of broad spectrum
insecticides, thereby reducing the impacts of these application on the environment and
non-target organisms.