Chapter 4 - 2

02 Environmental Science

Genetic Alteration of Plants

Plant geneticists have been manipulating the genetic structure of plants for hundreds of years.

In some cases, are selectively bred to create heartier, healthier plants.

Using similar techniques, plant geneticists can also alter a plant’s genetic structure to protect against pests or other factors.

By introducing new features into a plant species, food shortages as a result of pests can be avoided.

Chemical barriers are some of the most common features introduced by geneticists to protect plants against pests.

By selectively cross-breeding particular plants, scientists can create a unique genetic strain that produces a chemical repellant to the pests that would otherwise consume it.

Following the American Revolutionary War, the Hessian fly became an epidemic in the Midwest portion of the country.

The files laid their eggs on the leaves of wheat plants.

The larvae hatched from the eggs would work their way down the leaves and eat the stem of the plants.

This feeding pattern weakened the stems of wheat plants, causing them to break.

In response to impending wheat shortages, researchers introduced a trait through crossbreeding that allowed the wheat to produce a chemical.

The chemical killed Hessian fly larvae when they ate the wheat’s leaves.

This prevented severe wheat shortages.

Alternatively, plant geneticists can use similar physical barriers to repel insects.

Certain plants have actual physical features that impede pests.

Leafhoppers are a common pest among smooth-leaf crops such as alfalfa, beans, and potatoes.

However, if vulnerable plants are selectively bred to make the leaves rougher; leafhoppers can be repelled.

It is also possible to genetically manipulate pest populations directly.

Introducing a large number of sterile males into a population drastically reduces reproduction.

Males are bred in a laboratory and then exposed to a slight amount of radiation, which renders them sterile.

The sterile insects are then released into an area, where they compete with virile males to reproduce with females of the species.

As a large percentage of the male insect population is sterile, the number of impregnated females is relatively low.

This significantly reduces the population of the pests’ next generation.

Screwworms, a species of fly that kills cattle by causing open wounds, has been combated by introducing sterile males to its population.

Finally, plant geneticists have begun manually manipulating the genetic structure of plants.

Using cutting-edge biotechnology, they can alter genes without crossbreeding.

By introducing new genetic elements with biotechnology, plants virtually overnight.

The makeup of plant viruses, for instance, has been introduced into the genetic structure of plants themselves, rendering them immune from the disease.

As knowledge of genetics increases and the ability to manipulate genes improves with technological advancements, the possibilities are nearly endless.

Food shortages can be averted, pests can be deterred, and plants can adjust to their environment.

With new discoveries, the process is becoming more streamlined.

Hopefully, with the aid of genetic manipulation, science may one day be able to stop hunger around the world.