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Asexual Reproduction Production of offspring without Fusion of sex

cells(gametes)

Requires only one parent

Offspring have 100% the same chromosomes as the parent. In other words, the offspring are exact

“clones” of the parent.

Most unicellular organisms

reproduce this way.

Mitosis

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Natural Methods Of Asexual Reproduction

In Nature, Plants Reproduce By Following Methods.

Budding

By Spores or Sporulation

Vegetative propagation

Apomixis

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Natural Method No.1 Budding

Example. Yeast

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Budding is a means of asexual reproduction whereby a new individual develops from an outgrowth of a parent, splits off, and lives independently.

Note: In yeasts the cell does not divide equally in two halves; instead, there is a large mother cell and a smaller daughter cell.

Yeast - budding

Natural Method No.2 Spore Formation or Sporulation

Happens in fungi, green algae, moulds

and non flowering plants (e.g. fern)

Spores are produced and each spore

develops into offspring which are identical

to parent

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Spores: Single, specialized cells which

are released from the parent -- they are enclosed in a protective case and develop when environmental conditions are favorable.

The formation of spores occurs in bread mold, mushrooms, mosses & ferns.

Fungi

Natural Method No.3 Vegetative Propagation

Vegetative propagation results in a

new plant that is genetically identical to the parent plant (a clone).

Seeds does not involves.

Examples: strawberry plant, vegetables, and crops.

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Natural Method No.4 Apomixis

Production of seeds without fertilization.

Sexual reproduction is replaced by Asexual reproduction.

Example. Dandelion etc.

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Artificial Methods Of Asexual Reproduction

Plants may asexually reproduce by diff. techniques. i.e.

By Cutting

Tissue culture (test tube cloning)

Protoplast Fusion

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Artificial Method No.1 Plant cuttings

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Vegetative reproduction is a type of asexual reproduction in plants that relies on multi-cellular structures formed by the parent plant. It has long been exploited in horticulture and agriculture, with various methods employed to multiply stocks of plants.

Artificial Method No.2 Tissue culture (test tube cloning)

In this technique plants with similar characters are produced, called “clones”.

New plant can produce from the pieces of tissues or oneparenchyma cell.

This cell divides to form a body, called callus. This callus consists of similar cells & from this root arise and cells

starts to produce diff. parts of plant body. This method is used in Orchards & Pinus trees to obtain wood.

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Advantages & Disadvantages Of Tissue cultureAdvantages Disadvantages

By this technique similar character are developed.

These plants have resistance against diseases,

By plant culture useful chemicals are obtained,

e.g. Shikonin.This chemical is used in chemical silk industry.

These plants are sterile, do not reproduce by sexual method.

This technique may cause change in the structure or number of Chromosomes.

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Artificial Method No.3 Protoplast Fusion technique of tissue culture

In this technique outer cell wall is removed around the protoplasts.

In some cases protoplasts are fused together, then their protoplasts are used for culture.

These protoplasts produce a wall around them, then they are changed into new plants.

This method is used in Potato & Wild night Shade plant.

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