Asexual Reproduction in Plants

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Science > Biology > Reproduction in Flowering PlantsYou are Here

Reproduction:

  • Reproduction is defined as a biological process in which an organism gives rise to young ones (offspring) similar to itself.
  • The offspring grow, mature and in turn produce new offspring. Thus, there is a cycle of birth, growth and death. Reproduction enables the continuity of the species, generation after generation.

Types of Reproduction

  • Asexual Reproduction: When offspring is produced by a single parent with or without the involvement of gamete formation, the reproduction is asexual.
  • Sexual Reproduction: When two parents (opposite sex) participate in the reproductive process and also involve fusion of male and female gametes, it is called sexual reproduction.

Characteristics of Asexual  Reproduction

  • In this method, a single individual (parent) is capable of producing offspring. A
  • As a result, the offspring that are produced are not only identical to one another but are also exact copies of their parent.
  • These offspring are genetically and morphologically identical to parents
  • The term clone is used to describe such morphologically and genetically similar individuals.
  • Usually followed by organisms with relatively simpler organizations

Types of Asexual  Reproduction:

Binary Fission:

  • In Protists and Monerans, the organism or the parent cell divides into two to give rise to new individuals.
  • Thus, in these organisms cell division is itself a mode of reproduction. Many single-celled organisms reproduce by binary fission, where a cell divides into two halves and each rapidly grows into an adult
  • e.g., reproduction in Amoeba, Paramecium, Viruses.

Asexual Reproduction in Plants

Budding:

  • In yeast, the division is unequal and small buds are produced that remain attached initially to the parent cell which, eventually gets separated and mature into new yeast organisms (cells). e.g
  • e.g. reproduction in  Yeast and hydra

Asexual Reproduction in Plants Yeast 01

Spores Formation:

  • Members of the Kingdom Fungi and simple plants such as algae reproduce through special asexual reproductive structures.
  • The most common of these structures are zoospores that usually are microscopic motile structures.
  • Other common asexual reproductive structures are conidia (Penicillium), buds (Hydra) and gemmules (sponge).In fungi and algae, specialized asexual reproductive units are formed.

Asexual Reproduction in Plants Spores 01



Natural Methods of Vegetative Propagation (Asexual reproduction):

  • Vegetative Propagation is an asexual method of reproduction in plants.
  • In plants, the units of vegetative propagation such as runner, rhizome, sucker, tuber, offset, bulb are all capable of giving rise to new offspring. These structures are called vegetative propagules.
  • Since the formation of these structures does not involve two parents, the process involved is asexual.
  • Tuberous Roots:
    • The roots of such plants have adventitious buds on their surface which sprout under favourable conditions to produce leafy shoots.
    • In Commercial Production these sprouts are separated and planted. Thus many plants can be obtained from a single root.
    • e.g. Sweet potato, Asparagus (Shatavari), Dahlia

Asexual Reproduction in Plants Tuberous Roots



  • Stem Tubers:
    • A stem tuber has many notches called ‘eyes’ on their surface.
    • Each eye actually a node and consists of one or more small axillary buds and reduced scale leaves.
    • After dormancy period the eyes which sprout under favourable conditions to produce leafy shoots.
    • In Commercial Production the tuber is cut into pieces, such that each piece has at least one eye. Then they are grown separately. Thus many plants can be obtained from a single tuber.
    • e.g. Potato, Ginger

Asexual Reproduction in Plants Stem Tubers

  • Runners:
    • Runner develops from the lower axillary bud of stem and thin elongated cylindrical wire-like structure with long internodes.
    • It creeps on the ground and becomes rooted at the nodes. Shoots are produced from upper sides of nodes.
    • After getting detached from a parent, such shoots grow as an independent plant.
    • e.g. Cynodon (doobgrass), Fragaria (strawberry), Oxalis

Asexual Reproduction in Plants Runners

  • Leaf
    • In bryophyllum, the leaf is succulent with crenate or notched margins.
    • Adventitious buds called epiphyllous buds or foliar buds are formed at notches at the tip of lateral veins.
    • These buds sprout and form leafy shoots and adventitious roots.
    • When such sprout falls on wet soil, they develop into independent plants.
    • e.g. Bryophyllum, Kalanchoe, Begonia

Asexual Reproduction in Leaf

  • Hazard due to Water Hyacinth (Terror of Bengal)
    • One of the most invasive weeds
    • Grows wherever there is standing water
    • Drains oxygen from water- leads to the death of fishes.
    • Introduced in India because of its pretty flowers & shape of leaves
    • Vegetative propagation occurs at a phenomenal rate

Asexual Reproduction in Water hycinth



Asexual Reproduction Terror of Bengal

Artificial Methods of Vegetative Propagation  (Asexual reproduction):

  • Cutting
    • In this method, a branch of plant part (stem, root or leaves) is cut with a node (primary meristem) on it. This piece of a branch is termed a cutting.
    • This cutting is buried in the soil.
    • The cutting is watered continuously.
    • This method is the cheapest and convenient method of vegetative propagation.

Asexual Reproduction Cutting

  • Grafting
    • In this method, the parts of two different plants are joined together in such a way that they unite and continue their growth as one plant.
    • The plant rooted to the soil and on which the part of the other plant is inserted is called a stock.
    • The other plant which is inserted on the stock is called Scion or graft.
    • Budding is a special case of grafting in which a single bid with a small part of a bark and living tissue is grafted on another plant.

Asexual Reproduction Grafting

The significance of Vegetative Propagation:

  • It is easy and cheaper method of multiplication.
  • The plants like banana, pineapple and grapes which do not produce viable seeds can be propagated by vegetative propagation only.
  • In this method, genetically similar plants are formed.
  • The yield can be increased by grafting high-yield variety on less yielding variety but which is adapted to the region.
  • This is a rapid method of propagation particularly for the plants having a long dormancy period.
  • It can be used to get clones of rare plants.
Science > Biology > Reproduction in Flowering PlantsYou are Here
Physics Chemistry  Biology  Mathematics

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