Mutant crop varieties therefore form integral parts of daily diets all over the world; are raw materials in industries; and contribute billions of dollars in additional income to farmers. The traits that confer superiority on the mutants over other cultivars include synergistic higher yields due to enhanced resistances to biotic and abiotic factors; improved nutrient use efficiencies; and nutritional and other quality traits. In being hardier and more nutrient use efficient and therefore requiring less agricultural inputs, several mutant crop varieties are more economical to grow and contribute to more environment friendly agriculture.