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Detailed study of Plant Propagation


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PLANT PROPAGATION Mr. V. Lenin Babu , M.Pharm .,( Ph.D ), Associate Professor, MLR Institute of Pharmacy, Hyderabad.


Propagation : Creating new plants from a variety of sources such as seeds, cuttings, bulbs and other plant parts. Plants are propagated by two methods; Sexual Method (Seed Propagation) Asexual Method (Vegetative Propagation)


Sexual Method (Seed Propagation) Pollen (male) egg (female) Seeds Plants are raised from seeds , such plants are called as seedlings .


Methods of seed propagation Broadcasting Dibbling Nursery bedding


For seed propagation seeds must be; Free from used seeds & extraneous matter


To ensure success in seed propagation; Collect the seeds in perfect ripe stage. Immediate plantation. Store in cool and dry place (seeds not used in propagation) Avoid long term storage, because it leads to loss of germination capacity. Ex: Short term storage of Cinnamon, Nutmeg and Cocoa . Drying of Seeds of Colchicum autumnale . Rapidly losses their germination capacity .


In some cases seeds are preconditioned with the help of Scarification . Ex: Seeds of Ipomoea purga (Jalap) – obtains 95% of germination in 8days . Slow germinating seeds – Soaked in water/0.2% of gibberellic acid for 48hrs . Ex: Ricinus communis (Castor seeds) .


Drastic methods; H 2 SO 4 /Partial removal of testa using grinding stone. Ex: H yoscyamus niger (Henbane seeds) . Pounding with coarse sand . Ex: Seeds of Cassia angustifolia (Indian Senna ) . Germination capacity- Rolled towel test. Excised embryo test.


Advantages : Most effective method. Increases genetic variation. Virus free plants. Long lived (Perennial trees). Bears heavily (Fruit plants). More sturdy. Cheap and easy to raise. Easy transportation. Disadvantages: Difficult to produce superior quality. Not uniform (growth and yield). Long time to produce seeds. Vegetative parts can’t be allowed.


Asexual method (Vegetative propagation): It is a process of asexual reproduction of a plant . The new plant is genetically identical to the parent . It can be done by 3 methods; Natural method. Artificial method. Aseptic methods of micropropagation or tissue culture.  


Natural method: New plants grow from parts of the parent plant. They include : Runners: Stems that grow horizontally above the ground. They have nodes where buds are formed. These buds grow into a new plant. Ex: Strawberries , Mint .


Roots: New plants will grow out of swollen, modified roots called tubers . Buds develop at the base of the stem and then grow into new plants . Ex: Jalap, Aconite, Potatoes , Cassava and Yams. 


Leaves: Leaves of some plants will grow into a new plant if they become detached from the parent plant. Other plants grow small plants called  plantlets  on the edge of their leaves . Ex: Trachyspermum ammi ( Ajowan ).


Bulbs : A bulb contains an  underground stem . Leaves are attached to the stem. These leaves contain much stored food . At the center of the bulb is an  apical bud . Also attached   lateral buds . The apical bud will produce leaves and a flower while the lateral buds will produce new shoots . As the plant grows and develops it will form a new bulb underground. Ex: Squill , Garlic, Lilies.


Artificial method: Cuttings: Part of the plant that is cut off of the parent plant. New roots and leaves will grow from the cutting. The shoot is cut at an angle. G rowth promoter may be used.   Ex: Vasaka


Grafting : 2 plants are used to develop a new plant with combined traits from the 2 parent plants . scion  is the above ground part of one plant. Stock is the rooted part of the second plant. The   scion  is attached to the  stock  which grows in to a new plant.


Examples: Cinchona ledgeriana scions are grafted on Cinchona succirubra root stocks , eventually giving a tree which produces bark rich in quinidine alkaloids . Grafting of female scions of Myristica fragrans on male stocks used to increase the proportion of fruit bearing plants in plantation.


Examples: Citrus species.


Grafting and budding notes: Cambial layers of stock and scion must meet. Parts must be held securely. Keep air out! Union heals by callus production from parenchyma cells. Adequate temperature for cell division.


Layering Ex: Climbing roses


Woody ornamentals such as camellia , oleander propagated by air layering.


Mound layering This method is successful with gooseberries and apple root stocks.


Micropropagation Utilizes small ‘explants’. Callus formation. Cell differentiation. First used on ferns, orchids and carnations.


Advantages: Uniform in growth and yield. No variation from parent plant. Harvesting is easy (Fruit trees). Seedless varieties (Ex: Grapes, pomegranates and lemon). Disease resistant trees. Modifying by root stocks and scion. Disadvantages: Not long lived. No new varieties.


Parts of plants used in Asexual method of propagation Bulbs : Squill , garlic. Corms : Colchicum, saffron. Tubers : Jalap, aconite, potato. Rhizomes : Ginger, turmeric. Runners : Peppermint, strawberry. Suckers : Pineapple, chrysanthemum. Offsets : Aloe, valerian. Stolons : Arrow-root, liquorice .

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