Download - REPRODUCING PLANTS CHAPTER 8 AGRISCIENCE AND TECHNOLOGY CHAPTER 8 AGRISCIENCE AND TECHNOLOGY
REPRODUCING PLANTS
CHAPTER 8
AGRISCIENCE AND TECHNOLOGY
CHAPTER 8
AGRISCIENCE AND TECHNOLOGY
TYPES OF PLANT REPRODUCTION
• SEXUAL REPRODUCTION - Involves using seed to propagate plants. Flowers are important because they contain the reproductive organs.
• ASEXUAL REPRODUCTION - Involves reproducing plants by using vegetative parts of the plant. Results in clones (genetically like their parents).
KINDS OF SEED
• MONOCOT - Plants having seed with one seed leaf, known as a cotyledon. Examples are corn, wheat, rice and all grasses.
• DICOT - Plants that have seed with two cotyledon. Examples are tomatoes, beans, petunias and carnations.
PARTS OF A BEAN SEED
• EXTERNAL
• Seed coat - Outer covering of the seed
• Hilum - 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.
PARTS OF A BEAN SEED
• INTERNAL:• Cotyledons - Bean seed has two ; contain food for
the embro.
• 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).
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 - Opposite side of the grain from the seed scar.
PARTS OF A MONOCOT SEED : CORN
• INTERNAL :• Endosperm - Where the food is stored for the embyo.• Radicle - Becomes the root system.• Hypocotyl - Connects the radicle with the food source.• Epicotyl - Forms the stem.• Cotyledon - Does not store food; absorbs food from
the endosperm.• Plumule - Develops into leaves.
PARTS OF A COMPLETE FLOWER
• Sepals - Outer part of the flower; covers the bud and protects it as it develops.
• Petals - Located just inside the sepals; attract insects which help with the fertilization process.
• Stamens - Male part of the flower; contains an anther that produces pollen, or sperm.
• Pistil - Female part of the flower; contains the stigma
FLOWERS
• PERFECT FLOWERS - Contain the stamen and pistil in the same flower.
• IMPERFECT FLOWERS - Flowers that lack either the stamen or pistil.
• Exception : Monoecious plants may have both male and female imperfect flowers on them. Corn is an example.
POLLINATION
• Transfer of pollen from an anther to a stigma of a flower of the same species.
• Pollen may be moved by wind, insects, birds and other natural means.
• Cross-pollination - When two different plants are involved.
• Self-pollination - Involves flowers on the same plant.
TYPES OF FRUIT
• FLESHY FRUIT - Have large fibrous structures surrounding the seed; apples, pears, blackberries, oranges and grapes are examples.
• DRY FRUIT - Fruit develops as a pod or in a hull; beans, peas, peanuts and cotton are examples of dry fruit. Pecans, acorns, corn, oats, wheat, elm trees are examples of hulls.
GERMINATION TESTING
• When a number of seeds sprout out of a set amount is called a germination test.
• Helps in determining the number of seeds to plant.
• Soil is the most widely growing medium; however greenhouses usually use “artificial” media.
CONDITIONS FOR SEED GERMINATION
• MUST HAVE THE FOLLOWING:
• MOISTURE
• TEMPERATURE
• OXYGEN
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: an example is seedless grapes.
EXAMPLES OF VEGETATIVE PROPAGATION USING
BELOW GROUND PARTS
• Potatoes are cut into sections with buds (eyes) and planted.
• Bulbs or corms are planted; multiply and new bulbs are pulled apart and planted separately.
METHODS OF ABOVE GROUND PROPAGATION
• LAYERING - Involves getting roots to grow from the stems of plants
• CUTTING - Involves using a short section of plant stem for propagation.
• BUDDING - Involves taking a bud from one plant and moving it to another.
• GRAFTING - Involves placing a section of the stem of one plant onto another plant.
QUALITIES OF GOOD SEED
• Purity - Contains only seed intended.• Contamination - Free of trash• Percent germination - Should be 90-100 %• Uniformity - Same size and shape• Damage - Seed coats should not be cracked• Free of disease - Healthy• Treatment - Treated to prevent disease• Reputation of grower and dealer