Genetic Erosion in Plants

Genetic erosion is the loss of genetic diversity in plant (and in animals) and it occurs when the unique gene pool of plant or animal species is gradually or drastically diminished or at a complete loss. The gene pool is the total genes, or genetic information, in a population of any given species. With genetic erosion there is a loss of particular individual genes, a certain gene combination or gene complexes. How dangerous is genetic erosion? Genetic diversity loss can occur naturally but the impacts are usually minor, but genetic erosion is of great concern as it is occurring at an unprecedented rate and the world's has lost many species mostly due to the impact of human developments. The largest driver of genetic erosion is species loss and the conversion of natural habitats which threatens populations by weakening them and can lead to eventual extinction.

Where there was once numerous varieties of crops grown, we now have only a few dominating the market. The shift to industrial agriculture has resulted in the decline of the genetic diversity of crops. The UN Food and Agriculture Organisation estimates that 75% of the genetic diversity in crops since the 1900's has been lost and 90% of crop varieties have disappeared from farmer's fields. This has happened in favour of varieties that uniformly ripen, last during shipping, appear flawless and have a longer shelf life. Traditional grain and vegetable varieties are key to future food security as the diverse gene pools make crops less susceptible to disease, pests and blight. Not only has the decreased genetic diversity increased crop vulnerability but new resistant varieties that are bred requires the germ-plasm of the old varieties are are being lost. Replacing local varieties with plants that wouldn't naturally occur there, such as plants from elsewhere or genetically modified (GM) plants has also contributed to genetic erosion. Farmers have favoured uniform farming by limiting crop varieties or using GM crops which has reduced the varieties found in traditional farming.

The research of plant genetic resources is critical to species
survival and food security for the future.

Attempts are being made to locate valuable genetic plant resources found in traditional species to prevent further genetic erosion and conserve them. Valued genes are known to exist in wild cereals retained in pockets around the Middle East, central Asia, the Caucuses and in little-explored habitats. In such remote places there are still people who grow traditional species of our food plants – these are local land races. The ancient genes in wild species can withstand dry, hot conditions and harsh winters, and may be the key to building crop resilience to climate change. The problem is finding the wild cereals in places of war and places of natural disasters which have completely destroyed crops and seeds banks. Here is where the storage of seeds to prevent the threat of genetic erosion by using ex-situ conservation seed banks has become very valuable and the scientists who search and collect such materials are contributing to global efforts to ensure our food security.

Seed research photo credit: <a href="http://www.flickr.com/photos/kewonflickr/7830949064/">Kew on Flickr</a> via <a href="http://photopin.com">photopin</a> <a href="http://creativecommons.org/licenses/by-nc-