Adventitious Roots

Abstract

The root system of a plant is composed of the primary, lateral and adventitious roots (ARs). Lateral roots always develop from roots, whereas ARs form from stem or leaf‐derived cells. AR development (ARD) is part of the normal development of the plant and occurs naturally, like in most monocotyledonous for which they constitute the main root system or in many dicotyledonous species that propagate vegetatively. Adventitious rooting is an essential step for vegetative propagation of economically important horticultural and woody species as it allows clonal propagation and rapid fixation of superior genotypes prior to their introduction into production or breeding programmes. Development of ARs is a complex process that is affected by multiple endogenous and environmental factors, including phytohormones, light, nutritional status, associated stress responses, such as wounding, and genetic characteristics. Key Concepts ARs are a prerequisite for vegetative propagation of plants. ARs arise from any organ of the plant but the root. ARs originate from different cell types depending on the organ or the species. Adventitious rooting is a complex quantitative genetic trait. ARs are the main root system for monocots. ARs can be adaptative response to environmental changes. ARs can be induced by interaction with micro‐organisms such as mycorrhizae or bacteria Auxin cross‐talks with other hormones to control adventitious rooting.