REPRODUCING PLANTS

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REPRODUCING PLANTS
Modified by the GA Agricultural Education
Curriculum Office July 2002
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Types Of Plant Reproduction

• Sexual Reproduction - Involves using seed to
  propagate plants. The flowers are important
  because they contain the reproductive organs.
• Asexual Reproduction Involves using the
  vegetative parts of the plant for propagation.
  The end result is a clone (a plant genetically
  similar to its parents).

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Types Of Seeds

• Monocot - Plants having seeds with one seed leaf,
  known as a cotyledon. Examples are corn, wheat,
  rice, and all grasses.
• Dicot - Plants having seeds with two cotyledons.
  Examples are tomatoes, beans, petunias, and
  carnations.

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Parts Of A Bean Seed

• External
• Seed coat - outer covering of the seed
• Hilum location where the seed was attached in
  the pod
• Micropyle - tiny opening near the seed scar where
  the pollen entered the ovule to form the seed

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Parts Of A Bean Seed (Cont.)

• Internal
• Cotyledons - contain food for the embryo two are
  found in the bean seed
• Radicle - becomes the root system of the plant
• Hypocotyl - connects the radicle and the
  cotyledons
• Epicotyl - forms the stem of the plant
• Plumule - develops the above-ground part of the
  plant (embryonic leaves)

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Parts Of A Monocot Seed Corn

• External
• Seed coat - protects the embryo
• Seed scar - where the corn grain was attached to
  the cob
• Silk scar found on the grain opposite the seed
  scar

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Parts Of A Monocot Seed Corn (Cont.)

• Internal
• Endosperm - where food for the embryo is stored
• Radicle - becomes the root system
• Hypocotyl - connects the radicle to the food
  source
• Epicotyl - Becomes the stem
• Cotyledon - absorbs food from the endosperm, DOES
  NOT store it
• Plumule becomes the leaves

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Parts Of A Complete Flower

• Sepal - Outer part of the flower covers the bud
  and protects it as it develops.
• Petal - Located just inside the sepals attracts
  insects which help in the fertilization process.
• Stamen - Male part of the flower contains an
  anther that produces the pollen (sperm).
• Pistil - Female part of the flower contains the
  stigma.

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Flowers

• Perfect Flowers Flowers that have the stamen
  and pistil in the same flower.
• Imperfect Flowers - Flowers that lack either the
  stamen or the pistil.
• Exception - Monoecious plants may have both male
  and female imperfect flowers on them. An example
  of this is corn.

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Pollination

• Pollination - The transfer of pollen from the
  anther to the stigma of the same flower.
• Pollen may be moved by wind, insects, birds, and
  other natural means.
• Cross-pollination - Pollination involving two
  different plants.
• Self-pollination Pollination involving flowers
  on the same plant.

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Types of Fruit

• Fleshy Fruit - Large fibrous structures that
  surround the seed includes apples, pears,
  blackberries, oranges, and grapes.
• Dry Fruit - Develops as a pod or in a hull
  includes beans, peas, peanuts and cotton (pods)
  also includes pecans, acorns, corn, oats, wheat,
  and elm trees (hulls).

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Germination Testing

• Germination Test The number of seeds that
  sprout from a set amount of seeds.
• Helps in determining the number of seeds to
  plant.
• Soil is the most widely growing medium.
• Greenhouses usually use artificial media.

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Conditions for Seed Germination

• The following are vital requirements
• moisture
• temperature
• oxygen

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Benefits of Vegetative Propagation

• True Traits Of Parents
• Assures that the new plant is identical to its
  parents.
• No Seed
• Some plants do not produce seed, for example -
  seedless grapes.

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Examples Of Vegetative Propagation Using Below
Ground Parts

• Potatoes with buds (eyes) are cut into sections
  and planted.
• Bulbs (corms) are planted.
• They multiply.
• New bulbs are pulled apart and planted
  separately.

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Methods Of Above Ground Propagation

• Layering Making roots grow from the stem of the
  plant.
• Cutting - Using a short section of a plant stem
  for propagation.
• Budding - Taking a bud from one plant and moving
  it to another.
• Grafting - Placing a section of stem from one
  plant onto another plant.

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Qualities to Determine Good Seed

• Purity Percent of the bag that is pure seed
  want a large percent purity.
• Contamination - Free of trash want as little
  contamination as possible.
• Percent germination Percent of seed that should
  germinate want it to be around 90-100
• Uniformity Seed of the same size and shape
  want as much uniformity as possible.

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Qualities to Determine Good Seed (Cont.)

• Damage Cracking, splitting, etc. want as
  little damage as possible.
• Free of disease Healthy want your seed to be
  proven free.
• Treatment - Treated to prevent disease good.
• Reputation of grower and dealer Want good
  reputation.