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Asexual reproduction in Plant.pptx

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Asexual reproduction in Plant.pptx

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Topic is Asexual reproduction in plant ,in Detail with proper diagram and example.
The diagram are taken form web browser and notes is taken from liable source, ref books and NCERT book.
I can assure you that if you go through this ppt then you will not need any Reference book to read or to make note.
Reference is Textbook of NEET and AIIMS "Botany"
so plz give me your valuable feedback.
Thank you

Topic is Asexual reproduction in plant ,in Detail with proper diagram and example.
The diagram are taken form web browser and notes is taken from liable source, ref books and NCERT book.
I can assure you that if you go through this ppt then you will not need any Reference book to read or to make note.
Reference is Textbook of NEET and AIIMS "Botany"
so plz give me your valuable feedback.
Thank you

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Asexual reproduction in Plant.pptx

  1. 1. CONTENT  Introduction about Asexual reproduction  Types of Asexual Reprodcution  Binary Fission  Budding  Sporulation  Fragmentation  Vegetative Reproduction/Propagation  Micropropagation.  Types of vegetative Reprodcution  Natural Method • stem • Leaves • Roots  Artificial Method • Cuttings • Layering • Grafting
  2. 2. ASEXUAL REPRODUCTION It is a mode of reproduction/multiplication in which new individuals develops from a single parent. Features of asexual reproduction: 1. As there is involvement of only one parent so it is uniparental. 2. It can occur with or without gamete formation but gametic fusion is absent. 3. The individuals produced are exact copies of each other and their parents because the new organisms produced inherit all of its chromosome from one parent. Moreover, it involve only mitotic division. Such a group of morphologically and genetically similar individual is called clone. 4. It can occur through unspecialised or specialised parts of parent. 5. Higher plant also exhibit this type of reproduction where it is known as Vegetative reproduction. 6. It is a simple and quick method of reproduction.
  3. 3. LET US DISCUSS DIFFERENT WAYS OF ASEXUAL REPRODUCTION:  Binary fission  Budding  Sporulation  Fragmentation  Vegetative reproduction/propagation
  4. 4. 1. BINARY FISSION  Occurrence: It occurs in many single celled organisms belonging to kingdom Monera (Bacteria), and Prostista (Amoeba and Paramecium).  Mechanisms : In this process, the parent organisms divides into two halves, each half forming an independent daughter organism. It means, the parent body as a whole forms reproductive unit and the parent continues living as two daughter individuals. Thus, here cell division itself is a mode of reproduction.  It involves amitosis in bacteria and mitotic division of nucleus in yeast and amoeba i.e., karyokinesis followed by division of cytoplasm i.e., cytokinesis resulting in the formation of daughter cells.  Depending upon the plane of division, binary fission is of the following types a) Simple Binary Fission(Irregular Binary fission):- Division can occur through any plane e.g., Amoeba. b) Longitudinal Binary Fission: The plane of fission passes along the longitudinal axis of the organism e.g., Euglena c) Transverse Binary Fission : The plane of this division runs along the transverse axis of the individual e.g., Bacteria, Paramecium, Diatoms.
  5. 5. 2. BUDDING. • Occurrence: Occurs in single celled organisms like yeast. • Mechanism : In this process unicellular structure develops an outgrowth (bud) on one side. Daughter nuclei produced through karyokinesis shifts into the bud. The bud grows, constricts at the base and separates. So bud remains attached initially to the parent cells which eventually separates and mature into new organisms (cells). • Unlike binary fission, cytoplasmic division is unequal and parental cell exists.
  6. 6. 3. SPORULATION o occurrence : These are formed by members of the kingdom fungi and simple plants such as algae. oType : The most commonly produced spores are zoospores and conidia. o Zoospores : These are microscopic motile spores that move by means of flagella formed under favourable condition. They are mot common asexual structure formed in algae. o In unicellular green alga, Chlamydomonas zoospores is pyramid shaped, anteriorly flagellated, resembling parents cells. o During zoospores formation parents cells starts behaving like sporangia.
  7. 7. Conidia : These are non-motile spores produced by special hyphal branches called conidiophores. These are most common asexual spores produced by fungi. In Penicillium conidiophores may shows branching and over these branches there is formation of flask shape structure called sterigmata (phialides). Each sterigmata produces/cuts a chain of conidia. Fig. : Asexual structure :Zoospores of Chlamydomonas. Fig. : Asexual structure : Conidia of Penicillium.
  8. 8. 4. FRAGMENTATION. Fragmentation is a form of asexual reproduction where an organisms spells into fragments. Each of these fragments develops into mature fully grown individual followed by mitosis. It occurs in some algae (Spirogyra), fungi and Hydra, etc.
  9. 9. 5. VEGETATIVE REPRODCUTION/PROPAGATION. •It is a method of multiplication in which a somatic part of the plants detaches from the body of the mother and develops into a new independent plant under suitable environmental conditions. •The detachable somatic part involved in vegetative propagation is called vegetative propagule. •There are two types of vegetative reproduction : A. Natural methods of vegetative reproduction : B. Artificial or Horticultural method of vegetative reproduction. A. Natural Methods of Vegetative Reprodcution : 1. Stem : i. Underground stem ii. Subaerial stem iii. Aerial stem iv. Bulbils 2. Leaves 3. Roots
  10. 10. 1. STEMS. i. Underground stem: (a) Tuber: it is a terminal portion of an underground stem branch which is swollen on account of accumulation of food. They possess buds over their nodes or eyes. This buds sprouts to produce new plantlets, when a stem tuber or a part of it having an eye is placed in the soil. E.g., Potato Fig. : Eyes of Potato (b) Rhizome: It is the main underground perennial stem. Buds present on the node take part for formation of new aerial shoot during favourable season of growth. E.g., Banana, Ginger.
  11. 11. (c) Bulb: it is an underground unbranched reduced disc shaped stem. Termininal bud is surrounded by several leaves e.g., Onion, Garlic. Fig. : Bulb of Onion (ii) Subaerial stem : (a) Offset : Short horizontal branch producing a cluster of leaves above and the cluster of roots below is called offset. It occurs in some aquatic plants. Breaking of offsets helps in propagation e.g., Eichhornia (water hyacinth), Pisita (water Lettuce). Fig. : Offset of water hyacinth
  12. 12. (b) Sucker : it arises by axillary bud of underground part of stem e.g., Chrysanthemum, Pineapple. (c) Runner : It is elongated, prostrate, sub-aerial branch with long internodes and roots at nodes. E.g., Grasses. Fig. : Sucker in Chrysanthemum Fig. : Runner of grass (iii) Aerial shoots : Each segment of stem having at lest one node can form a new plant. E.g., Sugarcane, Opuntia.
  13. 13. (iv) Bulbils : These are large size fleshy buds which are specialised for vegetative reproduction. For this bulbil must fall from the plant and reach the soil. They can be present at variable positions on plants. In Agave bulbils are modified floral buds that develop on the floral axis. e.g., Agave (century plant), oxalis, Ananas, Dioscorea, lily. 2. Leaves : Leaves of several plants having adventitious buds help in vegetative reproduction. In Bryophyllum adventitious buds arise from the notches present at margins of leaves. E.g., Adiantum (walking fern), Begonia, kalanchoe. Fig. : Bulbil of Agave Fig. : Bryophyllum. 3. Roots : It was discussed that one of the prerequisites for vegetative reproduction is presence of buds. Though bud is mainly the feature of stem but in some plants roots may also bear buds. These adventitious buds sprout to form new plants e.g., Dahlia.
  14. 14. B. ARTIFICIAL METHOD OF VEGETATIVE REPRODCUTION. 1. Cuttings : i) Stem Cuttings: it is a common artificial method of plant propagation. 20-30cm long pieces of one year old stems are cut and their lower ends are dipped in dilute auxin for several minutes before planting in the soil. The lower ends develops adventitious roots. Buds present over the exposed parts sprout and form the shoot system. e.g., Rose, Duranta, Cirtus, Clerodendron, Thea, Bougainvillea, Croton and China Rose ii) Leaf cuttings: Snake plant (Sansevieria) can be propagated by leaf cuttings. Leaves are cut transversely into two or three parts and planted in vertical position in the soil. For successful leaf cutting, besides induction of rooting, formation of adventitious buds is also important. iii) Root cuttings: They are long pieces of roots which are used to artificially propagate new plants. Ability to form adventitious roots and adventitious buds are pre-requisites. Roots are used in propagation of Lemon, Tamarind, Blackberry and Raspberry. Fig. : Stem cutting.
  15. 15. 2. Layering : •It is a type of rooting-cutting method in which adventitious roots are induced to develop on a soft stem while it is still attached to the plant. •It is carried out on one year old basal shoot branches commonly during early spring or early rainy season Layering is of following types a) Tip layering : It induces root formation and later growth of shoot tip e.g., Blackberry, Raspberry. b) Trench Layering : It develops a number of vertical shoots e.g., Walnut, Mulberry. c) Gootee (Air layering) : it is an ancient horticultural technique for propagation of tropical and subtropical trees and shrub where soft branches do not occur near the soil. METHOD : During early monsoon rains, 3-5 cm long ring of bark is removed form the basal region of a healthy and woody branch. It is covered by a thick plaster of grafting clay. Grafting clay is made of 1 part cow dung, 1 part finely cut hay or moss and two parts clay. To its added water and a small quantity of root promoting hormones like IAA, IBA or NAA. It is then wrapped in polythene. After 2- 3months roots appear. The shoot is now cut below the covered part and used for planting. E.g., Litchi, Pomegranate. Fig. : Tip layering Fig. : Trench layering
  16. 16. 3. Grafting: • Grafting is a technique of connecting two parts, usually a root system and a shoot system of two different plants in such a way that they unite and later develop as a composite plant. • It is used only in cambium containing eustelic plants. • A small shoot of plant with superior traits is employed. It is called graft or scion. The root system of the other plant is allowed to remain intact. It is called stock (Under stock). E.g., Mango, Apple, Citrus. Fig. : Grafting Various types of grafting a) Tongue (slice or whip grafting) : Oblique sloping cut or notch is given to both stock and scion. b) Wedge Grafting: V shaped notch.
  17. 17. c) Crown Grafting: Wedge shaped d) Approach Grafting : Two independently growing plants are brought together. e) Bud Grafting: Scion is a bud with a small piece of bark and cambium. Stock is given a T shaped cut. Bark is lifted to expose cambium. Bud is inserted and the bark is allowed to come back to its original position. Only the bud is exposed. The joint is treated with grafting wax and is bandaged. But sprouts after 3-5 weeks. Bud grafting is commonly practiced in apple, peach and rose Fig. : Crown grafting Fig. : Approach Grafting. Fig. : Bud Grafting. 4. Micropropagtion : Micropropagation is the raising of new plants from a small plant tissue with the help of tissue culture technique. Tissue Culture is the technique of maintaining and growing cells, tissues, etc. and their differentiation on artificial medium under aseptic condition inside suitable containers.

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