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