Plant Propagation
I. Sexual Propagation
   1. Seed propagation
      - most common method by which plants reproduce in nature
      - most efficient and widely-used method for cultivated crops, e.g. rice,
        coconut, papaya, tomato, orchid
      - seeds arise from the fusion of male and female gametes to form a single
        cell (zygote) within the ovule of a flower
   2. Embryo culture – done by aseptically removing the embryo from the seed
      and placing it in a sterilized culture medium to germinate
II. Asexual Propagation – involves reproduction from vegetative parts of plants
    and is possible because the vegetative organs of many plants have the
    capacity for regeneration
   1. Propagation by apomictic embryos
       Apomixis – production of embryo without meiosis and fertilization
            - embryos arise from vegetative cells within the ovule
   2. Separation and Division
      Separation – involves separating naturally detachable organs from the
                     mother plant
      Division – procedure wherein specialized vegetative structures are cut
                   into sections
                   modified organs which may be separated and/or
    divided:
       Bulb – a specialized underground organ consisting of a short, fleshy,
            usually vertical stem axis (basal plate) bearing at its apex a growing
            point or a flower primordium enclosed by thick, fleshy scales
            - e.g. tulips, lilies
       Bulbil – aerial plantlet formed on the axil of the leaves or flower stalk
            - e.g. agave
       Corm – a swollen base of a stem axis enclosed by the dry-scale leaves
      - e.g. banana, gladiolus, gabi
 Cormel – miniature corm which develop between old and new the corms
 Crown – part of a plant at the surface of the ground from which new
      shoots are produced
   - e.g. aster, Shasta daisy
 Offset (syn. offshoot) – a characteristic type of lateral shoot or branch
      which develops from the base of the main stem in certain plants (a
      shortened, thickened stem of rosette-like appearance)
   - e.g. Pistia sp.
 Pseudobulb – a specialized storage structure consisting of an enlarged,
      fleshy section of the stem made up of one to several nodes
      -e.g. Cattleya sp.
 Rhizome – a specialized structure in which the main axis of the plant
      grows horizontally at or just below the ground surface
   - e.g. banana, bamboo, sugarcane
 Runner – a specialized stem which develops from the axil of the leaf at
      the crown of a plant, grows horizontally along the ground, and
      forms a new plant at one of the nodes
   - e.g. strawberry, black pepper
 Slip – leafy shoot originating from axillary buds borne at the base of a
       plant or peduncle of the fruit
   - e.g. pineapple, cabbage
 Stolon – special modified stem, produced by some plants, that grow
       horizontal to the ground
   - e.g. Bermuda grass
 Sucker – adventitious shoot that arise from underground stems below
      the ground
   - e.g. banana, pineapple
 Tuber – a modified stem structure which develops below ground as a
      consequence of the swelling of the subapical portion of the stolon
      and subsequent accumulation if reserve materials
   - e.g. potato
 Tuberous root – thickened root which contain large amount of stored
      foods
      - e.g. cassava, sweet potato
4. Cutting – a portion of a stem, root, or leaf is cut from the parent plant, after
      which this plant part is placed under certain favorable environmental
      conditions and induced to form roots and shoots, thus producing a new
      independent plant
      - types:
       Root cutting – e.g. breadfruit, apple
       Stem cutting – types: hardwood, semi-hardwood, softwood, herbaceous
             cuttings
             - e.g. cassava, malunggay, coffee, rose
       Leaf cutting – e.g. snakeplant, begonia, African violet
       Leaf-bud cutting – e.g. black pepper, vanilla
5. Layering
      – a propagation method by which adventitious roots are induced to form
      on a stem while it is still attached to the parent plant
      - types:
       simple layering
       air layering or marcotting
       compound or serpentine layering
       mound or stool layering
       trench layering
6. Grafting
       - connecting parts of plants together in such a manner that they will unite
       and continue their growth as one plant
      -   Scion - short piece of detached shoot with one to several dormant
                  buds and which is to become the upper portion of graft
                  combination
      -   Rootstock – lower portion of graft which develops into the root system
                  of the grafted plant
      -   Interstock – a piece of stem inserted between scion and rootstock (to
                   avoid any incompatibility between scion and rootstock and/or
                   to take advantage of its growth controlling properties)
      -   types of grafting:
            whip or tongue grafting
            splice grafting
            side grafting
            cleft grafting
            wedge grafting
            bark grafting
            saddle grafting
7.        Budding
          - an asexual propagation, that like grafting, which involves joining 2 plant
            parts such that the size of the scion is reduced to only one bud and a
            small section of bark, with or without wood
          - types:
           shield budding (T budding)
           modified forkert budding
           inverted T budding
           chip budding
           patch budding
8. Inarching (Approach Grafting)
      - an asexual propagation technique in which plants are made to unite
        while growing on their roots
9. Tissue culture techniques other than embryo culture
     – can be started from a variety of plant parts which have cells capable of
       dividing
       - e.g. shoot-tip culture, meristem culture, endosperm culture
bmsalazar
27September2006