Pollen drift

Last updated
The stamen of a corn plant, showing the pollen. Corntassel 7095.jpg
The stamen of a corn plant, showing the pollen.

Pollen drift is the accidental cross-pollination of different varieties of crops through natural dispersal methods. The term is used almost exclusively when referring to strains of corn, and especially refers to the crossing of genetically modified crops with those that are not. For example, farmers who grow specialty crops may wish to preserve their genetic traits, such as an especially high oil content, without compromising the gene pool of the variety. Or, farmers may wish to avoid crossing a particular GMO crop that has been approved for export to a certain country, with non-GMO crops or other varieties of GMO crops that may not have the same approval. [1]

Genetically modified crops plants used in agriculture, the DNA of which has been modified using genetic engineering techniques

Genetically modified crops are plants used in agriculture, the DNA of which has been modified using genetic engineering methods. In most cases, the aim is to introduce a new trait to the plant which does not occur naturally in the species. Examples in food crops include resistance to certain pests, diseases, environmental conditions, reduction of spoilage, resistance to chemical treatments, or improving the nutrient profile of the crop. Examples in non-food crops include production of pharmaceutical agents, biofuels, and other industrially useful goods, as well as for bioremediation.

The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species.

Farmers who produce non-GMO crops and farmers who produce GMO crops for export are the most likely to be affected. Farmers whose non-GMO crops have been contaminated with GMO genes may lose their contracts or the rights to certain labeling. GMO exporters must meet the requirements of other countries, many of whom have stringent import controls regarding GMOs. [1]

Pollen drift can be avoided by careful examination of the geography of the area where the crop is to be grown combined with the study of the nature of the crop's pollen, the distance it can travel and via what methods, and how to plant their fields to avoid unwanted cross-pollination. [1]

Corn

Corn pollen is particularly prone to pollen drift. Corn plants release their pollen for around a week, and an entire field may take up to two weeks to completely release its pollen; pollen release usually shows a spike two to three days after half the plants have released their pollen. Each individual plant can produce 4 to 5 million individual pollen grains. Its pollen is among the largest particles that can be found in the air, and is spherical in its shape. It can drift up to half a mile and remain viable for several days in optimal conditions. These factors all create a considerable possibility for one corn field to cross-pollinate another, even if just a small percentage of the pollen shed by a given field drifts into a different field. [1]

Corn producers can reduce the chance of cross-contamination via pollen drift by separating fields by at least 150 feet (46 m); however, many identity preserved corn programs require that non-GMO fields be separated from GMO corn by a distance of at least 660 feet (200 m). [2] They may also utilize a technique called 'flooding' by surrounding their fields with a border of non-GMO corn, the theory being that these 'border rows' of corn will dilute any outside pollen, thus reducing the risk of cross-contamination. Producers can also alternate planting dates to prevent crops from releasing their pollen at similar times. [1] [3]

Related Research Articles

Genetically modified maize

Genetically modified maize (corn) is a genetically modified crop. Specific maize strains have been genetically engineered to express agriculturally-desirable traits, including resistance to pests and to herbicides. Maize strains with both traits are now in use in multiple countries. GM maize has also caused controversy with respect to possible health effects, impact on other insects and impact on other plants via gene flow. One strain, called Starlink, was approved only for animal feed in the US, but was found in food, leading to a series of recalls starting in 2000.

Agricultural biotechnology, also known as agritech, is an area of agricultural science involving the use of scientific tools and techniques, including genetic engineering, molecular markers, molecular diagnostics, vaccines, and tissue culture, to modify living organisms: plants, animals, and microorganisms. Crop biotechnology is one aspect of agricultural biotechnology which has been greatly developed upon in recent times. Desired trait are exported from a particular species of Crop to an entirely different species. These transgene crops possess desirable characteristics in terms of flavor, color of flowers, growth rate, size of harvested products and resistance to diseases and pests.

Genetically modified food

Genetically modified foods, also known as genetically engineered foods, or bioengineered foods are foods produced from organisms that have had changes introduced into their DNA using the methods of genetic engineering. Genetic engineering techniques allow for the introduction of new traits as well as greater control over traits when compared to previous methods, such as selective breeding and mutation breeding.

Pollination Biological processes occurring in plants

Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents are animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species it can produce hybrid offspring in nature and in plant breeding work.

Open pollination

"Open pollination" and "open pollinated" refer to a variety of concepts in the context of the sexual reproduction of plants. Generally speaking, the term refers to plants pollinated naturally by birds, insects, wind, or human hands.

Genetic use restriction technology proposed methods for restricting the use of GMOs to only activate in response to a given stimulus.

Genetic use restriction technology (GURT), also known as terminator technology or suicide seeds, is the name given to proposed methods for restricting the use of genetically modified plants by activating some genes only in response to certain stimuli, especially to cause second generation seeds to be infertile. The technology was originally developed under a cooperative research and development agreement between the Agricultural Research Service of the United States Department of Agriculture and Delta and Pine Land company in the 1990s and is not yet commercially available.

Seedless fruit

A seedless fruit is a fruit developed to possess no mature seeds. As consumption of seedless fruits is generally easier and more convenient, they are considered commercially valuable.

Cytoplasmic male sterility is total or partial male sterility in plants as the result of specific nuclear and mitochondrial interactions. Male sterility is the failure of plants to produce functional anthers, pollen, or male gametes.

Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, peas, and pansy this behavior is most widespread in the grass family. However, the largest genus of cleistogamous plants is Viola.

Since the advent of genetic engineering in the 1970s, concerns have been raised about the dangers of the technology. Laws, regulations, and treaties were created in the years following to contain genetically modified organisms and prevent their escape. Nevertheless, there are several examples of failure to keep GM crops separate from conventional ones.

Genetically modified food controversies Controversies over GMO food

Genetically modified food controversies are disputes over the use of foods and other goods derived from genetically modified crops instead of conventional crops, and other uses of genetic engineering in food production. The disputes involve consumers, farmers, biotechnology companies, governmental regulators, non-governmental organizations, and scientists. The key areas of controversy related to genetically modified food are whether such food should be labeled, the role of government regulators, the objectivity of scientific research and publication, the effect of genetically modified crops on health and the environment, the effect on pesticide resistance, the impact of such crops for farmers, and the role of the crops in feeding the world population. In addition, products derived from GMO organisms play a role in the production of ethanol fuels and pharmaceuticals.

Intensive crop farming

Intensive crop farming is a modern form of intensive farming that refers to the industrialized production of crops. Intensive crop farming's methods include innovation in agricultural machinery, farming methods, genetic engineering technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, patent protection of genetic information, and global trade. These methods are widespread in developed nations.

Genetic pollution is a controversial term for uncontrolled gene flow into wild populations. It is defined as “the dispersal of contaminated altered genes from genetically engineered organisms to natural organisms, esp. by cross-pollination”, but has come to be used in some broader ways. It is related to the population genetics concept of gene flow, and genetic rescue, which is genetic material intentionally introduced to increase the fitness of a population. It is called genetic pollution when it negatively impacts on the fitness of a population, such as through outbreeding depression and the introduction of unwanted phenotypes which can lead to extinction.

Genetically modified rice

Genetically modified rice are rice strains that have been genetically modified. Rice plants have been modified to increase micronutrients such as vitamin A, accelerate photosynthesis, tolerate herbicides, resist pests, increase grain size, generate nutrients, flavours or produce human proteins.

Plant breeding The art and science of changing the traits of plants in order to produce desired characteristics

Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to methods that make use of knowledge of genetics and chromosomes, to more complex molecular techniques. Genes in a plant are what determine what type of qualitative or quantitative traits it will have. Plant breeders strive to create a specific outcome of plants and potentially new plant varieties.

Genetically modified food in Europe

Genetic engineering in Europe has varying degrees of regulation.

Genetic engineering in Hawaii is a hotly contested political topic. The Hawaiian islands counties of Kauai, Hawaii and Maui passed or considered laws restricting the practice within their borders due to concerns about the health, the environment and impacts on conventional and organic agriculture.

Corn silk agricultural term

Corn silk is a common name for the shiny, thread-like, weak fibers that grow as part of ears of corn (maize); the tuft or tassel of silky fibers that protrude from the tip of the ear of corn. The ear is enclosed in modified leaves called husks. Each individual fiber is an elongated style, attached to an individual ovary. The term probably originated somewhere between 1850 and 1855.

DMH-11 Mustard

Dhara Mustard Hybrid-11, otherwise known as DMH - 11, is a genetically modified hybrid variety of the mustard species Brassica juncea. It was developed by Professor Deepak Pental from the University of Delhi, with the aim of reducing India's demand for edible oil imports. DMH - 11 was created through transgenic technology, primarily involving the Bar, Barnase and Barstar gene system. The Barnase gene confers male sterility, while the Barstar gene restores DMH - 11's ability to produce fertile seeds. The insertion of the third gene Bar, enables DMH - 11 to produce phosphinothricin-N- acetyl-transferase, the enzyme responsible for Glufosinate resistance. This hybrid mustard variety has come under intense public scrutiny, mainly due to concerns regarding DMH - 11's potential to adversely affect the environment as well as consumer health. DMH - 11 was found not to pose any food allergy risks, and has demonstrated increased yields over existing mustard varieties. Conflicting details and results regarding the field trials and safety evaluations conducted on DMH - 11 have delayed its approval for commercial cropping.

References

  1. 1 2 3 4 5 Thomison, Peter. "Managing "Pollen Drift" to Minimize Contamination of Non-GMO Corn, AGF-153". Ohio State University Extension Fact Sheet. Ohio State University. Retrieved August 16, 2013.
  2. "Study Helps Establish Buffer Zone for Genetically Modified Crops Pollen Drift". Colorado State University. July 14, 2003. Retrieved August 16, 2013.
  3. Nielsen, R. L. (March 2000). "Minimizing Pollen Drift & Commingling of GMO and non-GMO Corn Grain". Chat 'n Chew Cafe. Corny News Network. Retrieved August 16, 2013.