Genetic Erosion of Wheat (Triticum spp.): Concept, Research Results and Challenges

Abstract

Wheat is an important food crop in the world. It is also one of the top three global food crops produced after rice and maize that constitutes an enormously significant role with respect to global food security. Due to finite land resources that can be dedicated to agriculture global wheat production has been consistently dependent on genetic improvement of wheat germplasm across the world. Traditional plant breeding has been an important tool in increasing global food production by producing disease and stress resistant, high yielding and early maturing wheat varieties. Genetic erosion within and between crop species is a worldwide problem and it is mainly related to modern agriculture, whereby uniform and high yielding varieties are grown on large scale and replaced the landraces. In addition, climate change and drought, fire, war, etc. are some other causes of genetic erosion. Reduced soil fertility, reduced land size and expansion of improved common wheat varieties are the major causes. The current study looks in detail at the concept of genetic erosion and how the concept of genetic erosion relates to the general diversity trends in variety of wheat and how to suggest the way forward. Genetic erosion may occur at three levels of integration: crop, variety and allele. Genetic erosion as reflected in a reduction of allelic evenness and richness appears to be the most useful definition, but has to be viewed in conjunction with events at variety level.

Keywords: genetic erosion; wheat; modern bottle neck