Submitted to: Emirates Journal of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 18, 2012
Publication Date: January 1, 2013
Citation: Jaradat, A.A. 2013. Wheat landraces: A mini review. Emirates Journal of Food and Agriculture. 25(1):20-29.
Interpretive Summary: Old wheat varieties are better adapted than modern varieties to changing climate conditions because of their genetic structure, and adaptation to the environment. However, they have low yield, as compared to modern varieties, which is caused by their genetic variation and plant competition for water and nutrients. Wheat breeders, seed producers, farmers and consumers should be involved in all aspects of research and development of new wheat varieties using the genetic resources of the old ones. When farmers, breeders, and consumers participate in wheat improvement, they will be more successful than if breeders only are involved in wheat breeding and improvement. This method of plant breeding not only delivers improved varieties, but also opens venues of communication and collaboration between farmers and other stakeholders for the benefit of all. Old wheat varieties having multiple home uses are more likely to be conserved and sustainably utilized for the foreseeable future. Farmers and wheat enthusiasts will benefit from the practical information and guidelines in this review to conserve and improve wheat production and quality.
Farmers developed and utilized diverse wheat landraces to meet the complexity of a multitude of spatio-temporal, agro-ecological systems and to provide reliable sustenance and a sustainable food source to local communities. The genetic structure of wheat landraces is an evolutionary approach to survival and performance, especially under arid and semi-arid growing conditions and organic inputs. Historically, traditional farmers planted diverse assemblages of wheat landraces to lower the risk of failure and increase food security because they had limited capacity to control the spatially heterogeneous and temporally unpredictable environment. This practice led to the development of landrace meta-populations of wheat and the emergence of farmers' seed systems through which they accessed and exchanged diverse genetic material. Traditional management of wheat landraces contributed more to the conservation of a general level of diversity than to the conservation of genetically stable and distinct populations. Therefore, a wheat landrace is far from being a stable, distinct, and uniform unit; its diversity is linked to the diversity of the material sown in its immediate geographical area, and to the level and frequency of seed exchange among farmers. During the last century, the introduction of high-yielding varieties into and the structural changes in wheat farming systems led to the loss of genetic diversity and fragmentation of meta-population structures of wheat landraces. However, the persistence cultivation of some wheat landraces attests to their continued value to farmers, or to their competitive agronomic or nutritional advantage relative to modern varieties. For farmers to continue to grow, select, and manage local wheat landraces, and to reverse the fragmentation of their meta-populations, especially in their center of diversity, and allow evolutionary processes that mold landrace diversity to continue, their value should be raised to approximate or exceed the social value of high-yielding wheat varieties.