Genetic diversity is the variation occurred in genetic information, which depends on frequency and diversity of alleles among individuals within a population or a species. This phenomenon, which is also a part of the evolution process, allows the organisms to adapt to changing conditions and to survive. Populations with high allelic variability are more easily adaptable to changing environmental conditions. However, nowadays, constant use of populations with certain characters in the plant breeding and the uniformity of consumer demands are among one of the causes of genetic erosion. Loss of genetic diversity within a species can lead to loss of useful properties for human beings. If stress conditions such as disease or drought occur, the ability of a population to survive by adapting to this new condition is dependent on the presence of individuals carrying gene alleles that need to adapt to these conditions.
Part of the book: Genetic Diversity in Plant Species