Genetic Diversity and Heavy Metal Stress in Plants

Abstract

Heavy metals are considered as potent pollutants due to their widespread occurrence and their acute and chronic toxic effect on plants, animals, and humans. Variation is of great theoretical importance because it is the raw material on which natural selection acts to influence the evolution of hyperaccumulation. Natural variation is also important basis for the development of hyperaccumulation technology as it indicates the potential for improvement of plant traits through selective breeding, and provides variable genetic markers that can be studied by crossbreeding and molecular techniques. Although some degree of hyperaccumulation occurs in all members of the species that can hyperaccumulate heavy metals, quantitative genetic variation in the ability to hyperaccumulate have been reported, both between and within populations. Genetic diversity and variability analysis have proved to be an effective method in grouping accessions for effective management and utilization in genetic improvement of plants for enhanced phytoextraction. The existing genetic diversity in crops can be used for phytoextraction by identifying easily cultivable, high biomass yielding plants, and practicing selection in future generations.