Explant culture is a plant tissue culture technique where a small piece of tissue (called an explant) is taken from a plant—such as a leaf, stem, root, or meristem—and cultured aseptically on a nutrient medium under controlled conditions. The explant cells divide and grow to form callus or regenerate into a whole plant depending on the culture conditions and plant growth regulators used. This technique is widely used for micropropagation, genetic transformation, and studying plant development.