Morphology of root system
Roots are typically of non-green underground cylindrical structure forming the axis of the plant which gives rise to endogenous and does not possess leaves, nodes or buds.
Characteristics of the root system
- They normally constituted the descending part of the plant axis.
- These are the cylindrical structure which is non-green and do not have the distraction of nodes and internodes.
- Buds and leaves are absent and its functions root is covered by a root cap.
- Root branches develop from the interior of the parent root such and origin is called endogenous which is in contrast to exogenous or external origin in case of the stem.
- The roots are neutral or negatively phototrophic and positively hydrotropic and positively geotropic.
Parts of a typical root:
(1) Root cap:
- It is our thimble-shaped or cap-like parenchymatous multicellular structure which covers the root meristem.
- The cells of the root cap secret mucilage.
- The water lubricates the passage of roots through the soil.
- Without it, the tender route would be unable to penetrate the hard soil.
- Another function of the root cap is the protection of the root meristem from the friction of the soil particle.
- Route pockets function at balance in the aquatic plants which is finger glove-like covering at the root apices.
- These are structurally similar to the root caps but differ from the damaged or lost root pocket are not regenerated.
(2) Growing point Or meristematic zone
- It is about 1 mm in length.
- The growing point of the root is determined and lies protected below the root cap.
- The meristematic reason produces a new cell for the root cap and the based region of the root.
- Therefore it is essential for the growth of the root.
(3) Region for the zone of elongation
- It is about 4 to 8 mm in length.
- It lies behind the growing point.
- The cells of this region are newly formed cell which loses the power of division.
- They elongate rapidly.
- This increase the length of the root.
- This also causes the power of absorption of water and mineral salt from the soil.
(4) Root hair zone
- It also represents the zone of differentiation or maturation because a different type of primary tissues differentiates or mature in this reason like xylem and phloem, pericycle, endodermis cortex, epiblema etc.
- Root hair zone is 126 CM in length.
- Most of the water absorption occurs in this region.
- Some of the outer cells of this zone give rise to lateral tabular outgrowth called root hairs.
- The root hairs increase the exposed surface of the root for absorption.
(5) Region or zone of mature cell
- It forms the bulk of the route.
- The cells of this reason do not undergo any further change.
- The outermost layer of this region has a thick world or impermeable sales.
- So this region cannot help the root in water absorption.
- Its only functions to anchor the plant firmly in the soil.
Types of the root system
- There are two types of root system tap and adventitious.
- it is a mass of roots which develop from the radicle of the embryo.
- it consists of a tap root, secondary roots, tertiary roots and also rootlets.
- The radical itself grow up directly into the main or primary root.
- The persistent primary root is known as the taproot.
- they are formed in acropetal succession and oldest towards the base of the parent Root.
- Rootlets are the ultimate root branches.
- They bear root hair for absorption.
- The root system is of two types:-
- deep feeder tap root which penetrates the deeper layer of the soil.
- it is mostly found in trees.
- in surface feeders, the taproot does not elongate very much.
- the secondary roots spread to a greater extent mostly horizontal near the soil surface.
- the surface feeder tap root system of some annual plant consists of thin fibrous roots.
- it may be called a fibrous tap root system.
(2) adventitious root system
- The root that grows from any part of the plant other than the radicle or its branches is called adventitious roots.
- The branches like a taproot.
- a mass of adventitious roots along with their branches constituent and adventitious root system.
- the plant having adventitious root also developed primary root from the radical.
- However, it is short-lived and therefore does not produce taproot.
- fibrous roots are underground root which arises in group weather at the base of the erect steam for the notes of the horizontal stem.
- the main roots are of equal length.
- they give off small branches.
- both the main root and their branches are thin and thread-like.
- therefore they are called fibrous roots which do not penetrate deep in the soil are hens named as a surface feeder.
Function of roots
Primary or main functions
Roots take part in a succession of the plant and supporting the aerial shoot system.
- Absorption of water
Roots absorb water from the soil.
- absorption of minerals
Roots absorb mineral salts from the soil.
- production of soil erosion
Roots hold the soil particles firmly to prevent soil erosion.
The taking part in transport to absorb water and mineral to shoot system.
- Storage: It occurs in fresh roots.Conical-carrots, Napiform-Beat, Tuber-microbilis
- Extra or mechanical support: It is provided by several types of roots.Buttress roots- Bombax,Stilt roots- Maize
- Climbing: Roots help some of the weak stem plants to cling and hence climb of support.Ex- money plant.
- Nitrogen fixation: Nodulated roots of pea, bean, gram, methylation: Prop roots, knee roots
- Reproduction: By bearing adventitious buds on both tap roots and adventitious roots.
- Floating: By storing air sum of the function of the root as floats.
- Photosynthesis: As in propa, Tinospora
- Oxidation: The roots of some amphibious plant release Oxygen and oxidize the surrounding environment as for example rice.
Also, you can check the flowering plant characteristics and reproduction in-Study Notes on Sexual reproduction in flowering plants