CHAPTER 8 AGRISCIENCE AND TECHNOLOGY REPRODUCING PLANTS 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