What is mutagenesis in plant breeding? And what’s the difference between mutagenesis and genetic modification?

Genetic modification means plant characteristics are altered by introduction of a modified gene from another organism, an organism that need not even be from a plant. With mutagenesis there’s no introduction of foreign genes. Mutagenesis simply means natural or induced mutation. This increases genetic variation in plants, offering more scope for natural selection towards crops with higher yields, more disease resistance and earlier maturity. For instance mutagenesis allows plant breeders to develop oilseed rape varieties capable of producing healthier oils and OSR meal with a higher nutritive value.