7. Genetic Resources and Genetic Diversity

From PlantBreeding
Revision as of 23:43, 8 November 2011 by Plantbreedingadmin (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

7.1. CENTERS OF ORIGIN

7.2. CONCEPT OF GENE POOL

7.3. THE GENETIC VULNERABILITY OF FOOD CROPS

by Eric Elsner


The genetic vulnerability of food crops can be defined as the susceptibility of food crops to catastrophic losses from pests or pathogens due to the narrowing of their genetic base. One of the most frequently accused culprits responsible for the genetic vulnerability of the world’s food crops is the science of modern plant breeding. Other possible causes of genetic vulnerability include the loss of traditional agricultural lands caused by development, political instability, etc… This review will focus primarily on the genetic vulnerability of food crops as viewed from a plant breeding standpoint. According to Poehlman and Sleper (1995), “Plant Breeding is the art and science of improving the heredity of plants for the benefit of mankind.” As we examine the genetic vulnerability of the world’s food crops, we will discuss what is currently being done to address the issue and assess the status of the world’s plant genetic resources.

Before modern plant breeding is vilified as an evil that is quickly destroying plant genetic resources, it is important that two very important points are made. First, one must realize that the world’s population cannot be fed effectively using landrace or wild type plants alone. The science of modern plant breeding, including genetically modified organisms (GMOs) has allowed farmers to feed the world’s population except in cases of extreme climatic occurrences or political strife. Second, it is unclear how much responsibility modern plant breeding should shoulder for a reduction in the genetic variability of food crops. A review of the available literature on the subject will not lead to a clear answer. For example, Fu et al., (2005) reported that obvious genetic shift and allelic reduction was observed in cultivars of Canadian hard red spring wheat released over a span of 59 years from 1845 to 2004 and that these shifts coincided with six distinct breeding efforts that were undertaken. Christiansen et al., (2002) reported an increase in the genetic diversity of 75 Nordic spring wheat cultivars during the period ranging from 1900 – 1940. However, they further identify a loss of diversity in the same 75 cultivars occurring from 1940-1960 and another increase in diversity from 1960-2000. Lastly, Donini et al., (2000) investigated the genetic diversity of the dominant winter wheat varieties utilized in the UK from 1934-1994 and found little evidence pointing towards a significant narrowing of genetic diversity in the cultivars studied. They indicated that breeding resulted in a qualitative rather than quantitative shift in diversity (Donini et al., 2000). From these examples it is clear that when viewed from the perspective of the plant breeder, the issue of declining crop genetic diversity is by no means clear cut but must be an important consideration in order to protect the world’s food supply.


7.3.1. A HINT OF A PROBLEM

For at least the last 10,000 years humans have been selecting plants that performed better for them across a wide range of criteria including fruit size, number of fruit per plant, adaptation to specific environments, resistance to certain pests, and many other characteristics. It is reasonable to assume that thousands of plants were utilized and therefore a tremendous range of genetic diversity existed. Even as late as the middle of the 20th century, approximately 30,000 different cultivars of rice were grown in India (Kotschi, 2010). Mankind has shifted from relying on many species rich in genetic diversity to the place where we find ourselves today; with approximately 150 species in cultivation and 60% of the world’s food production coming from three species: rice, maize, and wheat (Kotschi, 2010). Simply put, fewer and fewer species are being used to feed an ever expanding population and the cultivars are becoming more genetically uniform (Harlan, 1975).

One may speculate that the current interest in the genetic diversity and vulnerability of crop plants was brought about by the United States’ experience with corn leaf blight in 1969 – 1970 (Brown, 1983). During 1970, a previously unknown race of Helminthosporium maydis destroyed approximately 15% of the U.S. corn crop. This widespread destruction was due to the disease susceptibility of the T cytoplasm used by a majority of the hybrid corn seed companies during this time (Brown, 1983). Following this outbreak, the National Academy of Sciences commissioned a survey that resulted in a statement of the genetic vulnerability of food crops. From the survey, it became evident that the genetic base of every major crop grown in the United States was very narrow. For example, in 1975, the U.S. soybean industry could trace its heritage to 6 introductions from the same region in China (Harlan, 1975).


7.3.2. HOW AND WHY BREEDING CAN CAUSE VULNERABILITY

Plant breeding by definition is the selection of superior genotypes and/or phenotypes over a period of time. This selection naturally results in a narrowing of the genetic base of the plant in question. Even if the breeder has introduced alleles from wild types or landraces to his target crop, he/she must then begin the process of “weeding out” the alleles that are undesirable. This weeding out of undesirable alleles is once again narrowing the genetic base of the line. If a breeder is working with a species that has previously been a target of breeding research, the breeding materials will likely be elite varieties that are currently in use (Brown, 1983). A breeder typically intermates the best varieties available and selects superior progeny from the mating. The continual use of the best varieties as parents naturally narrows the gene pool to only those alleles that are available from the elite parents and therefore tends to decrease the genetic variation of the population (Brown, 1983). It is not hard to understand the breeder’s reasons for following this path. Farming is a business and a farmer needs to produce maximum yield for the least amount of input in order to run a profitable business. In order to attain this goal and be able to farm for multiple years, farmers must have access to crops that have favorable qualitative traits such as disease or pest resistance and favorable quantitative traits such as high yield, resistance to environmental stresses, favorable grain moisture at harvest, favorable test weight, and a crop that matures uniformly in order to allow for mechanical harvest (Khoury et al., 2010). In response to this need, plant breeders work to produce high yielding, elite cultivars that are tailored to the farmer’s needs.

Modern plant breeding is a business as well and Gepts and Hancock (2006), report that approximately 75% of plant breeders are employed by private industry. Multi-national seed companies employ thousands of breeders who are tasked with creating new and improved varieties on an almost yearly basis in order for their parent companies to compete for market share and to please company shareholders. In the private sector, each company is in a race of sorts with its competitors to introduce improved varieties to the marketplace in order to compete for market share. Essentially the same is true in the public sector where funding for many plant breeding projects is received from outside sources and progress towards improved cultivars via genetic gain is expected in order for continued funding to occur.

Given the time constraints often placed on breeders, and when we take into account that a typical breeding cycle for many agronomic crops may take up to seven to ten years from cross to cultivar, it is not hard to understand why breeders rely on elite lines for their parental stock. For instance, if a corn breeder in the mid-western United States would like to develop a cultivar with resistance to a certain pathogen, the logical step would be for the breeder to take an existing elite line that already contains a suite of traits that are adapted to the mid-west and introgress resistance for the pathogen of interest into the elite line. This method would be much more efficient and streamlined as opposed to starting with a wild-type or landrace with a broader genetic base and breeding for the suite of traits that already exist in the elite line. In most instances, the elite lines will already contain most of the desired alleles and it is only necessary for the breeder to introgress a few specific alleles into the elite line or to further the breeding program of the elite line and make further phenotypic selections. Elite lines are the product of extensive research from both private and public funds. To expect a breeder to ignore these lines is to expect that breeder to not use all of the tools at his/her disposal.


7.3.3. TOWARDS DECREASING VULNERABILITY

If it is logical to assume that the plant breeder can increase genetic vulnerability by decreasing genetic variability then that same breeder can also reverse the trend and decrease genetic vulnerability by increasing genetic variability. One method used by breeders to increase the genetic variability of crop plants is to use crop wild relatives (CWR). Crop wild relatives have been enormously useful to plant breeders and to modern agriculture by allowing breeders to tap into a broad pool of genetic diversity (Hajjar and Hodgkin, 2007). Generally speaking, wild relatives have poor agronomic performance and are not typically used as the foundation for any breeding program (Hajjar and Hodgkin, 2007). However, plant breeders have had significant success using the CWR of modern crops to introgress favorable alleles into elite lines with the most common use being using CWR as a source of disease and pest resistance (Hajjar and Hodgkin, 2007). Hajjar and Hodgkin (2007) conducted a survey of the introduction of genes from CWR into cultivars of crops of major importance to the world food supply. The crops surveyed were: rice, wheat, maize, barley, sorghum, millet, cassava, potato, chickpea, cowpea, lentil, soybean, bean, pigeon pea, banana, tomato, sunflower, lettuce, and peanut (Hajjar and Hodgkin, 2007). Examples of wild genes being included in a released cultivar were found in every crop surveyed with the exception of soybean, pigeon pea, sorghum, and lentil with over 60 wild species identified as having been used to derive over 100 beneficial traits (Hajjar and Hodgkin, 2007). Current examples of CWR genes being used in cultivars include genes that convey resistance to leaf and stem rust, powdery mildew, and wheat streak mosaic virus in wheat, and resistance in sunflower to imidazolinone and sulfonylurea chemicals resulting in cultivated hybrids sold under the “Clearfield” trade name (Hajjar and Hodgkin, 2007). In 2010, three soybean plant introductions were found to have unique resistance to peanut root-knot nematode and it is hoped that these plant introductions can be used to improve the current resistance levels in elite lines (Yates et al., 2010).

Typically, a breeder identifies a trait that he/she would like to introgress into an elite line and then screens available germplasm for the trait of interest and selects potential parents based on the phenotype of the CWR. This type of system works well for traits controlled by one or a few genes with disease resistance being an important example. For traits controlled by multiple alleles, the situation is more complex. Breeders who are using CWRs as donors of favorable alleles contributing to quantitative traits such as yield or stress tolerance are almost certainly leaving behind some desirable alleles if they select parents based purely on phenotype. Recent advances in genomics and genome mapping are allowing breeders to shift from selection based solely on phenotype to selection based on the presence of useful genes (genotypic selection) (Tanksley and McCouch, 1997). One would assume that a high yielding parent would contain most of the genes for high yield and that a low yielding parent would not make a substantial contribution to the yield of the progeny of a cross. However, when molecular markers are used to identify loci controlling yield for a population derived from this type of cross, the results are contrary to what is expected. DeVicente and Tanksley (1993) found that while most of the “high yield contribution” comes from the high yielding parent, there are almost always some loci with alleles contributed by the inferior parent. One implication of this discovery is that assessing the breeding value of an accession based solely on its phenotype is likely to be misleading when one is dealing with quantitative traits and that potential parents should be evaluated using molecular markers and quantitative trait loci (QTL) analysis to identify useful genes/loci (Tanksley and McCouch, 1997). Tanksley and McCouch (1997) further report that using this technique and a breeding technique referred to as the advanced backcross QTL method in tomato led to the creation of lines that contain specific loci from the wild species Lycopersicon hirsutum and that these lines outperform the original elite cultivar by 48% when grown in different environments around the world. It is clear that the technology exists to confer alleles from CWR into modern elite lines either through phenotypic or genotypic selection. The obvious conclusion is that genetic diversity is important and plant breeders must have access to CWR in order to introduce new genes and characteristics into new cultivars. Therefore it is important to briefly review the state of the world’s plant genetic resources.


7.4. CONSERVATION OF PLANT GENETIC RESOURCES

More than 70 years ago, Vavilov noted the important role that crop relatives play as a source of genes (Vavilov, 1940). The two means of plant genetic resource conservation are in gene banks (ex situ) and in nature (in situ) with ex situ being vitally important for breeders who need ready access to germplasm (Cohen et al., 1991). In situ conservation of genetic resources on a global scale seems to be increasing with the number of protected areas in the world increasing from 56,000 in 1996 to 70,000 in 2007 with an increase in total area from 13 million to 17.5 million km2 (FAO, 2009). In 2009, there were more than 1,750 gene banks around the world with at least 130 of these holding more than 10,000 accessions each (FAO, 2009). Approximately 1.4 million accessions have been added worldwide since 1996 bringing the total number of accessions held to approximately 7.4 million with roughly 30% of these holdings being unique (FAO, 2009). One of the largest ex situ collections is the United States National Plant Germplasm System (US NPGS) which currently holds approximately 450,000 accessions of 10,000 species of the 85 most commonly grown crops (Smale and Day-Rubenstein, 2002). In 1997, the United States dedicated approximately $20 million to germplasm acquisition and preservation (Tanksley and McCouch, 1997). These data are encouraging for the long term as they speak to the world’s growing commitment to conserve plant genetic resources in both in situ and ex situ situations. The plant breeding community is moving in the right direction with respect to plant genetic resource conservation but more work remains. As always, regional and world politics continue to play a role in how resources are collected and shared and, as reported by the Global Crop Diversity Trust, a major constraint affecting resource conservation is the availability of the resources needed for the collection, storage, and regeneration of germplasm (Khoury et al., 2010).


CONCLUSIONS

In this review, we have discussed the genetic vulnerability of food crops through the lenses of the plant breeder. The plant breeder plays an important role in determining the level of genetic variability that is contained in our food crops. It is clear that by using traditional techniques and cutting edge genomics, plant breeders have the ability to and are currently introgressing wild-type genes and loci into today’s elite cultivars thereby potentially decreasing the vulnerability of some of our food crops. It seems equally clear from the available literature that efforts have been and are continuing to be made to protect the world’s crop plant diversity both in ex situ and in situ settings. As with every other topic of any importance, there are those who would have the reader believe that the situation is dire and possibly hopeless along with those who would say that there is nothing at all to worry about. As is usually the case, the answer lies somewhere in the middle and the case of the genetic vulnerability of food crops is no different. The genetic vulnerability of our food crops is an issue that we must continue to take seriously. We must take steps to minimize the potential impact of a narrow genetic base for our crops and this author believes that we are currently taking those steps.

7.5. GERMPLASM UTILIZATION IN PLANT BREEDING

7.6. OWNERSHIP OF PLANT GENETIC RESOURCES AND THE EFFECTS OF OWNERSHIP RIGHTS ON PLANT BREEDING

by Emily C. Pierce


As the demand for agricultural productivity continues to rise, there is an increasing pressure on plant breeders to develop new varieties that are higher yielding and able to produce in more challenging environments. The world is not only facing rapid population growth, but also a dwindling supply of water and arable land. It is the responsibility of plant breeders to develop cultivars that are capable of higher yields with limited resources. In order to do this, breeders rely on plant genetic resources to introduce desirable traits (Smale and Day-Rubenstein, 2002). Plant genetic resources are the functional units of heredity found in plants that are actually or potentially valuable (Fowler, 2001). These resources include wild relatives and landraces as well as commercial varieties that can serve as the platform for further improvement (Le Buanec, 2005). Without these plant genetic resources, breeders would struggle to find sources of new traits. Because environmental and biological challenges are constantly evolving, breeders cannot predict what resources they might require in order to meet the needs of the future. Therefore, it is important that a diverse collection of plant genetic resources is well preserved, and that these resources remain accessible to breeders (Smale and Day-Rubenstein, 2002).

Although plant genetic resources were traditionally regarded as being the common heritage of mankind, there has been a shift towards awarding property rights to these resources and restricting their availability. There is a possibility that such restriction could hinder the efforts of plant breeders. However, property rights can help to stimulate interest and innovation in plant breeding due to monetary incentives. How society decides to deal with the complex issues surrounding ownership of plant genetic resources will strongly influence how plant breeding is carried out in the future.


7.6.1. THE NEED FOR EXCHANGE OF PLANT GENETIC RESOURCES

The open use of agricultural genetic resources has historically played an important role in breeding to create plants with a diverse range of desirable characteristics (Roa-Rodríguez and Van Dooren, 2008). The genetic variation that breeders need to introduce these characteristics is often available only through the exchange of plant genetic resources. This exchange is necessary because some areas of the world, especially the centers of origin for crop species, have richer resources of genetic diversity. These resources have thus frequently moved between countries (Falcon and Fowler, 2002).

Crop genetic resources are a combination of the efforts of many people over many years, and thus in the past these resources have been exchanged as part of a common heritage that belongs to the public rather than to any single person or group. The concept of common heritage is a logical consequence of the inherent nature of plant genetic resources, which are easily transported and reproduced (Brush, 2007). This relatively unrestricted transfer of diverse genetic materials has allowed crops that are major food sources worldwide to travel far from their origins. The majority of crops that some countries now rely on are not indigenous crops, but have been introduced by this free exchange (Falcon and Fowler, 2002). Free exchange of plant genetic resources has therefore played an important role in supplying food for the world in the past, and this need is only increasing. Research has also shown that crop breeding programs in developing countries, where much of the increased food need is concentrated, are especially dependent on international germplasm exchange programs (Brush, 2007). Not only do plant breeders need a wide base of genetic resources to meet the world’s needs, but individual farmers also rely on these resources to ensure their own food security (Cooper, 2002).

Plant genetic resources have also become increasingly important as informational goods rather than as tangible goods. Although tangible plant genetic resources such as seeds have been important in the past, the genetic information that codes for the inheritance of certain traits is now of greater importance to plant breeders. These informational resources are becoming increasingly valuable, and their exchange is necessary to facilitate future innovation (Roa-Rodríguez and Van Dooren, 2008).


7.6.2. REASONS FOR INCREASED RESTRICTION OF PLANT GENETIC RESOURCE EXCHANGE

Although plant genetic resources were previously regarded as the common heritage of mankind, this is no longer the case. The recent trend has been a shift towards ownership claims that lead to a restriction of open access (Le Buanec, 2005). This restriction is not necessarily negative. One of the reasons for awarding property rights is to provide incentives to individuals or groups to participate in plant breeding, which should lead to more investment in breeding overall (Thiele-Wittig and Claus, 2003). Some other factors causing this shift in thought are related to the development of biotechnology and the ability to transfer genes; these advances have led to legislation that grants patents for many types of biological materials. The awarding of these patents is in stark contrast to the traditional free access to wild relatives and landraces. In the 1970s, the Plant Variety Protection (PVP) Act in the United States gave breeders of new varieties a protection similar to that that a patent would provide, given that the variety was somehow different from current varieties and was reproducible. However, PVP protection does not prevent the use of the protected variety in breeding programs. Following a court case that made a genetically modified microorganism patentable, there was a rush of patent applications for biotechnological “inventions.” Intellectual Property Rights were granted for genes, molecular constructs, and traits. These events led to increasing concern that plant genetic resources currently available for use by the public might become patented and inaccessible. Countries have responded to this concern by trying to claim materials that have traditionally belonged to the public and by limiting international agreements that allow access to these materials. This could put public germplasm collections at risk if fewer resources are part of the public domain. The increase in Intellectual Property Rights involving plant “inventions” has also led to a large increase in the merging of small companies into a few large applied biological science firms. These firms have a significant number of patents on plant genetic resources and control seed distribution, making it difficult for new genetic resource development companies to survive. These patents also make it difficult for research institutions to access these resources (Falcon and Fowler, 2002).

Another cause in the decline of the use of common heritage is that some countries associate this concept with imperialism. This perception is a result of the imbalance between the free flow of genetic diversity from developing countries where it naturally occurs and the subsequent sale of products derived from these resources by developed countries back to the developing countries for a profit (Le Buanec, 2005). This imbalance between the free flow of genetic resources from some countries and the high price of improved cultivars under patents/plant variety protections from others has led to an increase in political tensions. The controversy has arisen because although plant genetic resources that have been worked with and made distinct are eligible for PVP, the raw materials are not. This led to a situation in which countries whose inhabitants had developed germplasm over many years were giving this germplasm away under the common heritage rule, but were then having to buy the protected varieties created from this germplasm (Roa-Rodríguez and Van Dooren, 2008). There is a strong perception that developed countries have taken advantage of developing countries. The increase in Intellectual Property Rights for biological materials exacerbated this situation. Developed countries claimed ownership over genetic resources provided by developing countries, and developing countries lacked the appropriate means to acquire any reward for their contributions (Falcon and Fowler, 2002). As developing countries became aware of the economic value of their genetic resources, they began fighting to restrict access to these resources. Conflict has therefore arisen because although there is a trend towards patenting biological materials and improved cultivars, the groups holding these patents still want to have free access to the genetic resources that can be used to create or improve these cultivars (Rodríguez and Van Dooren, 2008). The common heritage idea has therefore declined to some degree due to the unidirectional nature of the flow of unimproved plant genetic resources from areas naturally rich in biodiversity (Falcon and Fowler, 2002).


7.6.3. POLITICAL DEVELOPMENTS IN THE STRUGGLE FOR OWNERSHIP OF PLANT GENETIC RESOURCES

In order to fully understand the debate over ownership of plant genetic resources, it is important to have some knowledge of the legislative attempts that have been made to settle these issues. Legislation regarding ownership of plant genetic resources can be traced back to 1930, when the United States passed the Plant Patent Act, which gave protection to vegetatively propagated crops. As the breeding industry became more commercialized, there arose a need for some form of regulation of plant genetic resources on an international level. This led to the International Convention for the Protection of New Plant Varieties (UPOV) in 1961. One important outcome of this convention was the establishment of Plant Breeders’ Rights, which gives ownership of sale and marketing rights of new commercial plant varieties to the breeder. Another significant effect of this convention was that it provided a way to remove plant genetic resources from common use. In 1970, the United States provided protection equivalent to that of the UPOV with the Plant Variety Protection Act. Plant Variety Protection systems do provide exemptions to breeders for further research and to farmers so that they can save seed if they are using it on their own land (Roa-Rodríguez and Van Dooren, 2008). This is in contrast to utility patents. Following a Supreme Court decision in 1980, living organisms are eligible for these patents, which do not include a “Breeder’s exception” to allow use of patented material in breeding programs (Le Buanec, 2005). The main difference between utility patents and plant patents or plant variety protection is the scope of the protection. Plant patents and plant variety protections are narrower and are variety specific. On the other hand, utility patents, which are much more difficult to obtain, protect the use of inventive concepts and are thus able to protect more than one variety containing these concepts. Utility patents are much broader in scope, but also require a lot of time and money to acquire (Williams, 1986). This could put public research entities at a disadvantage if they do not possess the legal or financial resources that a large corporation would to obtain this kind of patent. The differences between plant patents, utility patents, and plant variety protection are summarized in Table 1 (Williams, 1986).

In 1983, the Food and Agriculture Organization of the United Nations organized the International Undertaking on Plant Genetic Resources agreement, which attempted to negate some of the consequences of the ability to obtain patents on living organisms. The undertaking tried to return to the idea of common heritage and hoped to promote cooperation among nations in the use of plant genetic resources (Cooper, 2002). It also spelled out the concept of Farmer’s Rights (Roa-Rodríguez and Van Dooren, 2008), which aim to minimize individual ownership of plant genetic resources (Van Overwalle, 2005). Farmer’s Rights also include the idea that farmers should receive compensation from a general conservation fund for their role in developing plant resources. Unfortunately, participation in this agreement was voluntary and little progress was made (Aoki and Luvai, 2007). In 1992, the Convention on Biological Diversity met in a political climate of tension regarding the unequal exchange of plant genetic resources and biodiversity. Developing countries felt a need to protect their resources from exploitation, and thus the convention replaced common heritage with a philosophy of national sovereignty. Since this convention, countries have been racing to make laws positioning themselves as the suppliers of genetic resources and restricting access to these resources. Under this system, negotiations for the transfer of genetic resources must go through the country of origin (Falcon and Fowler, 2002).

In 1994, the Food and Agriculture Organization began negotiations to implement a legal agreement regarding ownership of plant genetic resources. In 2001, the International Treaty on Plant Genetic Resources for Food and Agriculture was created (Falcon and Fowler, 2002). The treaty took over seven years to complete, because of the challenge of respecting the rights of national sovereignty over resources while also ensuring that these genetic resources are accessible (Cooper, 2002). This treaty aims to create a multilateral system in which countries cooperate to allow access to resources to other countries in exchange for a portion of the profits made from anything incorporating these genetic resources. This money will be put into an international fund that will be used in projects such as germplasm conservation, etc. (Falcon and Fowler, 2002). The access to resources is based on terms agreed upon by both parties and the country must provide informed consent (Cooper, 2002).

7 6 1.jpg


This treaty may help to facilitate transfer of resources, but it still has some drawbacks. Although it covers most major crops, a few important crops, especially those important in developing countries, are not included because countries thought they might profit more from not including these crops and selling the resources through another avenue. For example, China withheld soybean, which is an important crop worldwide (Falcon and Fowler, 2002). Developing countries suffer the most as a result because they are more likely to lack the resources to obtain plant genetic resources that are not included in this system. Excluded crops will likely be transferred based on national sovereignty, which could make access more restricted. On the other hand, this treaty does back up the international status of the valuable collections held by the Consultative Group for International Agricultural Research (CGIAR). The CGIAR centers have some of the best collections of genetic resources, including resources of regionally important crops, and the materials are freely available upon request (Falcon and Fowler, 2002). The Convention on Biological Diversity did not specifically address the ownership of these collections, and there was a legitimate concern that countries might demand the return of germplasm or restrict its distribution on the basis of national sovereignty. This would have meant fewer plant genetic resources available for plant breeding. However, the Food and Agriculture Organization signed agreements in 1994 to establish these collections as “in-trust.” Under these agreements, the CGIAR centers do not own the collections, but are responsible for their upkeep and distribution. These agreements prevent anyone from seeking Intellectual Property Rights over the germplasm in the CGIAR centers. This was an important step in ensuring that these vital collections remain accessible (Gotor et al., 2010). The treaty also includes measures to work towards the sustainable use and conservation of plant genetic resources (Cooper, 2002). Despite its flaws, the International Treaty on Plant Genetic Resources for Food and Agriculture does attempt to provide some regulation to germplasm transfer and could prevent the creation of unnecessarily restrictive national legislation (Falcon and Fowler, 2002). Lastly, in the Trade-Related Aspects of Intellectual Property Rights agreement, which came into force in 1995, developing countries agreed to try to create an Intellectual Property Rights system but also maintained the right to not allow patents on plants, animals, and biological materials (Gepts, 2004).


7.6.4. POSSIBLE CONSEQUENCES OF THE RESTRICTION OF PLANT GENETIC RESOURCE EXCHANGE

The restriction of plant genetic resource flow has the potential to prevent the movement of germplasm between nations. As mentioned previously, most countries depend on genetic resources from other countries. Legal measures restricting the continued exchange of this material will thus be detrimental to all countries.

One consequence of the struggle for ownership rights is that national sovereignty over plant genetic resources has led to the creation of overly restrictive laws in some countries. Benefit-sharing can also lead to an increased emphasis on monetary benefits. On the whole, this can lead to a decrease in access and a decrease in collections of plant genetic resources (Roa-Rodríguez and Van Dooren, 2008).

The ability to obtain patents on biological materials also has consequences on plant breeding. Patent law helps to provide motivation to invent and commercialize new products by protecting the inventor from competition for a period of time (Van Overwalle, 2005). It also encourages investment in plant genetic resources and the creation of companies participating in this area of research. Because the budgets of public research institutions are increasingly tight, it is important to have plant breeding research in the private sector. Intellectual Property Rights are needed to encourage private investment (Srinivasan, 2003). In addition, the high-cost and high-risk nature of plant biotechnology research makes this financial incentive even more important (Figg, 1995). However, patenting of biological materials also inhibits the freedom of others to use the most improved germplasm. Because most patents occur in developed countries, this could put developing countries at greater disadvantage (Falcon and Fowler, 2002). In addition, farmers need plant genetic resources in order to adapt to changing conditions, and removing their access to these resources through patents might limit the role of farmers in developing diversity in the future (Eyzaguirre and Dennis, 2007). Additionally, because patents are valid only in the nation that issues them and many countries lack patent laws for biological materials, trade might be further restricted if patent holders do not want to release their materials into an area where they will not be protected (Falcon and Fowler, 2002). Patents might also lead to less breeding research involving traits for which there are many patents for fear that the outcomes of the research would fall under patent claims. There might also be a decrease in funding for breeding research that will not be patentable (Correa, 1995).

Another important consequence of removing the common heritage philosophy is increased cost in obtaining resources. Increased transaction costs due to ownership rights could put poor countries even further behind because of their inability to access the protected materials and technologies (Falcon and Fowler, 2002). The developing countries of the world, despite the fact that most of them are located in genetically diverse regions, are now the largest borrowers of plant germplasm. These countries are dependent on seed banks in developed countries, but access is increasingly difficult now that the common heritage system is disappearing (Aoki and Luvai, 2007). Less informed rural populations are also less likely to have the resources to claim ownership, and thus might lose access to germplasm (Eyzaguirre and Dennis, 2007).

Lastly, it is important to note another aspect of the issue of plant genetic resource exchange: the role of traditional communities and their knowledge. These communities protect the biodiversity of wild relatives of crop plants because they recognize the communal good that comes from possessing many varieties (Eyzaguirre and Dennis, 2007). The common heritage philosophy is common in these communities and seed is frequently exchanged (Brush, 2007). An increase in private ownership of germplasm could be harmful to this system, because if plant genetic resources are not freely traded, it makes less sense to maintain these wild relatives for the public good. Improvements in plant genetic resources are also the result of community efforts, which makes it impossible to assign property rights. Private property rights are not in sync with the traditional structures that have maintained plant genetic resources in the past, and thus traditional knowledge may not receive the compensation that it deserves (Eyzaguirre and Dennis, 2007).

Figure 1. Timeline of important political developments in the formation of property rights for plant genetic resources.


7.6.5.CONCLUSION

The access to plant genetic resources has been a vital part of plant breeding and the development of modern agriculture. Although property rights on plant genetic resources can serve a purpose, the trend towards increasing legal restriction on this access could be detrimental if breeders are unable to use the best germplasm available in their breeding programs. This restriction could be especially threatening to breeding programs in developing countries that are now net importers of plant germplasm. This conflict is complex, and negotiations over ownership rights are ongoing. It will no doubt be challenging to find a solution that meets the needs of all groups involved.


REFERENCES

Aoki, K., and K. Luvai. 2007. Reclaiming common heritage treatment in the international plant genetic resources regime complex. Michigan State Law Review 2007:35-70.

Brown, W.L. 1983. Genetic diversity and genetic vulnerability - an appraisal. Econ. Bot. 37:4-12.

Brush, S.B. 2007. Farmers' Rights and protection of traditional agricultural knowledge. World Development 35:1499-1514.

Christiansen, M.J., S.B. Andersen, and R. Ortiz. 2002. Diversity changes in an intensively bred wheat germplasm during the 20th century. Molecular Breeding 9:1-11.

Cohen, J.I., J.T. Williams, D.L. Plucknett, and H. Shands. 1991. Ex situ conservation of plant genetic resources: global development and environmental concerns. Science 253:866-872.

Cooper, H.D. 2002. The International Treaty on Plant Genetic Resources for Food and Agriculture. Review of European Community & International Environmental Law 11:1-16.

Correa, C. 1995. Sovereign and property rights over plant genetic resources. Agriculture and Human Values 12:58-79.

DeVicente, M.C., and S.D. Tanksley. 1993. QTL analysis of transgressive segregation in an interspecific tomato cross. Genetics 134:585-596.

Donini, P., J.R. Law, R.M.D. Koebner, J.C. Reeves , and R.J. Cooke. 2000. Temporal trends in the diversity of UK wheat. Theoretical and Applied Genetics 100:912-917.

Eyzaguirre, P.B., and E.M. Dennis. 2007. The impacts of collective action and property rights on plant genetic resources. World Development 35:1489-1498.

Falcon, W.P., and C. Fowler. 2002. Carving up the commons--emergence of a new international regime for germplasm development and transfer. Food Policy 27:197-222.

FAO. 2009. Draft second report on the world's plant genetic resources for food and agriculture. pp. 51-53.

Figg, E.A. 1995. Intellectual property protection for plant research in the USA: a cornucopia of opportunity. Current Opinion in Biotechnology 6:139-141.

Fowler, C. 2001. Protecting farmer innovation: The Convention on Biological Diversity and the question of origin. Jurimetrics J. 41:477-488.

Fu, Y.B., G.W. Peterson, K.W. Richards, D. Somers, R.M. DePauw, and J.M. Clarke. 2005. Allelic reduction and genetic shift in the Canadian hard red spring wheat germplasm released from 1845 to 2004. Theoretical and Applied Genetics 110:1505-1516.

Gepts, P. 2004. Who owns biodiversity, and how should the owners be compensated? Plant Physiol. 134:1295-1307.

Gepts, P., and J. Hancock. 2006. The future of plant breeding. Crop Sci. 46:1630-1634.

Gotor, E., F. Caracciolo, and J. Watts. 2010. The perceived impact of the in-trust agreements on CGIAR germplasm availability: An assessment of Bioversity International's institutional activities. World Development 38:1486-1493.

Hajjar, R., and T. Hodgkin. 2007. The use of wild relatives in crop improvement: a survey of developments over the last 20 years. Euphytica 156:1-13.

Harlan, J.R. 1975. Our vanishing genetic resources. Science 188:618-621.

Khoury, C., B. Laliberté, and L. Guarino. 2010. Trends in ex-situ & in-situ conservation of plant genetic resources: a review of global crop and regional conservation strategies. Genetic Resources and Crop Evolution 57:625-639.

Kotschi, J. 2010. Reconciling agriculture with biodiversity and innovations in plant breeding. Gaia-Ecological Perspectives for Science and Society 19:20-24.

Le Buanec, B. 2005. Plant genetic resources and freedom to operate. Euphytica 146:1-8.

Poehlman, J., and D.A. Sleper. 1995. Breeding field crops. Iowa State University Press. Ames, Iowa.

Roa-Rodríguez, C., and T. Van Dooren. 2008. Shifting common spaces of plant genetic resources in the international regulation of property. The Journal of World Intellectual Property 11:176-202.

Smale, M., and K. Day-Rubenstein. 2002. The demand for crop genetic resources: international use of the US National Plant Germplasm System. World Development 30:1639-1655.

Srinivasan, C.S. 2003. Concentration in ownership of plant variety rights: Some implications for developing countries. Food Policy 28:519-546.

Tanksley, S.D., and S.R. McCouch. 1997. Seed banks and molecular maps: unlocking genetic potential from the wild. Science 277:1063-1066.

Thiele-Wittig M., and P. Claus. 2003. Plant variety protection--A fascinating subject. World Patent Information 25:243-250.

Van Overwalle, G. 2005. Protecting and sharing biodiversity and traditional knowledge: Holder and user tools. Ecological Economics 53:585-607.

Vavilov, N.I. 1940. The New Systematics. J. Huxley, Ed. Clarendon, Oxford.

Williams, S.B. 1986. Utility product patent protection for plant varieties. Trends in Biotechnology 4:33-39.

Yates, J.L., R.S. Hussey, S.L. Finnerty, and H.R. Boerma. 2010. Three soybean plant introductions possess unique resistance to peanut root-knot nematode. Crop Sci. 50:118-122.