The preservation of genetic variation has become an important subject for many species. Various species of plants, animals, and microorganisms have been collected and stored, so the immense species variation might not be lost. The culture of cells and tissue, an area within biotechnology, is being used for the maintenance of live collections of the most varied types of plant species of economic importance or others at risk for extinction. For instance, the preservation of the genetic diversity of cassava is accomplished at tissue culture laboratories, where thousands of different varieties and species are maintained in small petri dishes. In the Frozen Zoological Garden in San Diego, California, there are live cellular lineages of species of several families of mammals, many close to extinction. It is expected that in the near future, cloning techniques will be used to regenerate whole animals from the cells. Had tissue culture technologies not been developed, the required space and costs to preserve rare species would be many times larger, limiting the number of species that could be preserved.

The preservation of microbial diversity has also been made possible by biotechnological techniques. If the bacteria, fungi, and viruses had to be maintained in their traditional hosts, only a small fraction of the biodiversity of microorganisms could be preserved. The germplasm banks of bacteria and fungi require a relatively small and rudimentary laboratory for preservation. The main objectives of microorganism gene banks are related to the preservation of species for subsequent laboratory studies.

Until the 1940s, the centers of origin of crop species and animals were considered limitless sources of genetic variability. After World War II, agriculture in developing countries suffered great changes. The expanded use of improved varieties resulted in the reduction of traditional varieties, a process called genetic erosion. The expansion of the agricultural frontiers also contributed to the risk of loss of the wild relatives of crop species.

According to a study carried out by the National Academy of Sciences in the United States, of approximately 3,000 possible plant species, only 20 to 30 constitute the basis of agriculture. For example, amaranth has high economic potential and has been recommended as a species that deserves more attention from plant breeders, with the objective of improving the plant to make it more valuable for commercial use. This requires the removal of undesirable traits and the improvement of other traits to allow for improved production.

The process of genetic erosion also occurs with many other species of flora, fauna, and microorganisms, and it is the first sign indicating possible species extinction. Environmental deterioration initially results in local extinction and later culminates with the global extinction of the species. For instance, well before species vanish, a small number of survivors could result in inbreeding of the population. Inbreeding results from intermating between related individuals that causes the generation of less fit individuals with a greater likelihood of genetic defects. Biotechnology can help in the diagnosis of genetic erosion before any conventional techniques. This can be achieved by DNA analyses that quantify the remaining genetic diversity (see Chapter 9, “Molecular Markers”). However, as each organism has a different genome, these methods would have to be developed for each species. This technique has been used with success in the study of wolf species, fish, cattle, macaws, whales, and other animals. In many cases, the studies were used to justify the creation of new refuges where such species dwell.

The term germplasm is vague and imprecise. However, germplasm has been defined as the entire hereditable material or the whole genetic makeup of an entire species. In other words, germplasm is all the existent diversity for a considered species. It is essentially biodiversity at a genetic level.

Two basic methods exist for germplasm conservation: ex situ and in situ. Gene banks function as ex situ conservation, where a sample of the genetic variability of a species is preserved in an artificial environment, outside of its normal habitat. In general, the seeds of plant species are stored in environments at low temperature and humidity. In these conditions, their viability can be preserved for several decades. Several gene banks around the world function as centralized storage areas for the germplasm of certain species. For instance, the USDA has a facility in Fort Collins, Colorado, that was specifically designed for long-term storage of important plant species. Other locations house working collections of germplasm from more specific species, such as the National Small Grains Germplasm Research Facility in Aberdeen, Idaho, which holds a working collection of wheat, barley, oats, rye, rice, triticale, and wheat relatives. This and other storage areas maintain germplasm diversity while allowing researchers to use the materials for plant improvement purposes. When there is a need for more long-term preservation, such as for preserving some specific types of plant tissue used in tissue culture or preservation of pollen, cryopreservation in liquid nitrogen at –196°C is the appropriate alternative. This is the storage method used in the Fort Collins National Seed Storage Laboratory.

In the in situ collections, the germplasm is preserved in its natural habitat. Many in situ gene banks are not recognized as such, mainly due to the terminology they receive (i.e., biological reserve, national park). Obviously, not every national park is a gene bank if the preservation of resources is not monitored, or if it is created for preservation of an entire ecosystem and not a certain species. A typical example of an in situ gene bank is located in Mexico, where 140,000 hectares in the mountains of Manantlan were designated as a biological reserve of Zea diploperennis (perennial diploid teosinte), a wild relative of maize. Its population is monitored periodically to detect any risk for loss of genetic diversity.

The importance of biodiversity becomes most evident during crises, as when a plant disease epidemic occurs, varieties of a crop species are susceptible to the pathogen, and no other resistant varieties exist. In these situations, the plant breeder usually looks to gene banks or at the centers of diversity of the crop for resistance sources that can be used in their crop breeding programs. Several varieties of rice, tomato, potato, and other species were developed using genetic resources from gene banks.

Plants constitute a rich source of therapeutically important products. Only 10 percent of plant species have already been tested for pharmaceutical value. About 120 medicines commonly prescribed by doctors are based on plant extracts. Some of the most important medicines used by humans have a history that traces back to medicinal plants collected from wild flora, and others are just now beginning to be discovered.

Aspirin is one example of the health benefits provided by plants. This medicine is based on acetyl-salicylic acid, a very common analgesic. Its history began with the Greek doctor Hypocrites, who in the fifth century B.C. used a bitter powder to treat pain and lower fever. This mystical powder was collected from the cork of Salix (Figure 12-1), a tree of the family Salicaceae. Although the mode of action of aspirin was only unraveled in the 1970s, this medicine has been used as a painkiller and to improve the elasticity of the circulatory system for millions of people. If this species had gone extinct before that discovery, man would have never known the valuable medicine. In fact, Americans annually consume about 80 billion aspirin tablets.

Figure 12-1. Salix sp., species from which aspirin was originally extracted.

Another example of the use of a plant extract is eye drops used for treatment of glaucoma. The active ingredient of the eye drops, pilo carpine, is extracted from Pilocarpus pinnafolius, a native species of northeast Brazil. Pilocarpine was originally used by native Brazilians to induce sweating (Figure 12-2). A pharmaceutical company owns a farm of 3,000 hectares in Barra da Corda, Brazil, of which 400 hectares are planted with 15 million Pilocarpus pinnafolius trees for the production of pilocarpine salts.

Source: Image courtesy of Raintree Nutrition Inc., www.raintree.com.

Figure 12-2. Pilocarpus pinnafolius produces pilocarpine, an active ingredient in the treatment of glaucoma.

N-Tense is another example of a therapeutic product made from medicinal plants in the Amazon rainforest. The plant extracts in this formula have been documented around the world to have antitumorous, antibacterial, anticancerous, immunostimulant, and antiviral properties (Figure 12-3). Some of the species used in this product include Physalis angulata, Annona muricata, Scoparia dulcis, Maytenus ilicifolia, Guazuma ulmifolia, and Momordica charantia, among others. These are just a few of several herbal medicines reported in the literature.

Source: Image courtesy of Raintree Nutrition Inc., www.raintree.com.

Figure 12-3. N-Tense, produced with plant extracts from Amazonian species.

The history of biodiversity collection dates back to 1500 B.C., when Egyptian rulers gathered plant species from their military expeditions. Charles Darwin, the renowned naturalist of the 19th century, accomplished one of the most famous trips for biological collection. During his travels on the ship the HMS Beagle, he collected samples of everything that interested him, from which he elaborated the Theory of the Evolution, the foundation of modern biological research. More recently, Nicolai I. Vavilov, a Russian scientist in the beginning of the 20th century, also collected samples of plant species from five continents, with which he established the Theory of the Center of Origin of the Crop Species.

None of those famous expeditions were legally or morally questioned. Today, the paradigms and laws have changed, and biopiracy is considered a crime. Biopiracy is the unauthorized appropriation of any biological resources. The extraction of aromatic, ornamental, or medicinal plants without the proper authorization is considered biopiracy. Natural resources primarily from Africa and South America are becoming increasingly valued in the international market. In the 1500s, Brazilian wood was prized for making red dyes; today, targeted Brazilian species number about 50,000 plant species, 534 mammals, 3,000 fishes, approximately 1,700 birds, 500 amphibians, and 470 reptiles. The wealth of Brazilian biodiversity makes the country a valuable source of genetic diversity. Every year, thousands of tourists, scientists, environmentalists, and biologists travel around the world under the umbrella of ecological tourism. Although this type of travel has improved research on biodiversity, it has also caused problems relating to biopiracy.

Scientists and pharmaceutical companies are obtaining several patents using plant extracts from different regions around the world. Recently, the English chemist Conrad Gorinsky received a worldwide patent for two pharmaceutical products: Rupununine, extracted from seeds of the Octotea rodioei, for birth control; and Cunaniol, a nervous system stimulant, extracted from Clibadium sylvestre. The use of the plants is part of the traditions of the native Wapixana Indians, who live in the Brazilian state of Roraima. Several other bioprospecting projects are underway in Africa and other places to identify plant extracts, animal toxins, and microorganisms for different purposes such as production of plastics or ore purification and fermentation processes.

When a sample of a species is collected illegally and a new drug or an isolated gene from that sample is patented, the patent can be revoked. If there is proof that the active ingredient used in the new drug was in public use, even if restricted to an indigenous tribe, revocation of the patent is possible. The great dilemma in patenting a natural product is that pharmaceutical companies take advantage of the ethnobiological knowledge of indigenous populations, and later, the companies are the only ones to collect profits from the marketing and production of the drugs.

To prevent such exploitation, regulations are being made worldwide to govern the use of biological diversity. In 1992, the United Nations Conference on Environment and Development (ECO 92) met in Rio de Janeiro, Brazil, with representatives from 120 countries. This conference recognized the national sovereignty of the nations and the genetic resources within their borders. Beyond this international work, the national laws of each country further govern the conservation and development of biodiversity within their respective boundaries. The Brazilian Congress recently recognized the importance of the protection of its biodiversity. This came after an accord with some multinational companies relating to the development of medicines resulting from the exploration of plants and microorganisms from the Atlantic rainforests and the Amazon.

Only 20 years ago, legal aspects related to the collection of samples of plants, microbes, and animals were largely ignored. In most cases, researchers simply made a trip to the place where the species of interest could exist in nature, collected the samples, and returned to their laboratories. Clearly laws didn't exist to regulate that practice. Sometimes, researchers obtained informal authorization from the local authority or from the landlord where the samples were collected. The days of locating, collecting, and returning home are running out, at least legally in most countries. More often it is today considered biopiracy.

Legal mechanisms should be developed to protect the biodiversity of the world. The mechanisms should promote the conservation of biodiversity and its use for the well-being of mankind. Developed countries and many others have taken the lead to ensure germplasm preservation for years to come. Extensive efforts are being made to characterize, catalog, and store the germplasm resources collected over many years from all over the world. Further steps are being taken to guarantee the preservation of the biodiversity of ecosystems and centers of origin for future research. Biotechnology will benefit from the world's biodiversity, while creating a means of preservation and continuation of the diversity of life found around the world.

There is an incredible amount of biodiversity worldwide, and much of it is relatively unknown. Despite the actions to explore this diversity, steps are being taken to characterize and preserve this valuable resource.