Tap Root System

Tap Root System

Definition of Tap Root System

A single dominant root developing from the radical of the embryo vertically underground the soil.

More About Tap Root System

  • The plant root system generally grows vertically downwards under the ground
  • It is a single prominent root and is also known as main root or primary root
  • It is persistent, i.e. it is retained throughout the life time of the plant
  • The germination of the seed gives rise to the first root
  • This root is known as radical
  • Tap root system develops from this radical
  • The primary root gives off many lateral branches known as secondary roots
  • These secondary roots further branch to give rise to tertiary roots
  • Terttiary roots further branch into rootlets and they bear root hairs for absorption
  • The tap root generally grows deep down inside the soil, when compared to the fibrous roots
  • It is mostly found in conifers and Dicotyledonous plants
  • Most of the tap roots are generally modified roots, which serve as storage (carbohydrates, generally starch) organs
  • The tap roots are categorised into four types depending upon their modification as follows:
    • a) Conical: The shape of root is like cone wide at the top end and tapering towards the bottom end. Example: Carrot
      b) Fusiform: The root is widest at the middle when compared to the tapering ends at top and the bottom like a spindle. Example: Radish
      c) Napiform: The root is more or less spherical, broadest at the top and a small and very thin at the bottom. Example: Turnip
      d) Tuberous: The root is thick and fleshy with no definite shape. Example: Cassava, Mirabilis

  • It is difficult to uproot the tap root when compared to the fibrous roots