REPRODUCING PLANTS Modified by the GA Agricultural Education Curriculum Office July 2002

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).

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.

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

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)

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

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

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.

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.

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.

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).

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.

Conditions for Seed Germination The following are vital requirements: 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, for example - seedless grapes.

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.

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.

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.

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.