Sexual Plant Propagation

Definition Propagation-to reproduce or increase in number

Types of Propagation: Sexual Uses seeds Requires the union of pollen (male sex cells) and egg (female sex cell) in the ovary Asexual Produces exact duplicates of the plant Uses part of the plant, such as leaf, stem, or root Asexual propagation is possible because each individual cell of a plant has all characteristics of the entire plant and can re-grow missing parts

Propagation from Seeds: Benefits Quick Inexpensive Easy Special requirements Scarification-weakening of the hard seed coat Ex: sandpaper, scratching or acid bath Cold shock-moist, cold rest period for 8 weeks or longer Light Darkness **Therefore, always follow the planting instructions**

Composition of seeds: Seed coat Outside covering that protects the embryonic plant Makes transportation and storage possible Endosperm Stored plant food The first start of growth in a seed Embryo (embryonic plant) New plant that is developed as a result of fertilization Extends root and seed leaves to form a new plant

What’s needed for Germination? Temperature Moisture Air Light or absence of it

Process of Germination Seed absorbs water Seeds proteins activated Radicle (root) emerges Plumule or embryonic shoot emerges Leaves form and food production begins

Monocot Seeds Seed coat-protection Endosperm-a source of energy Embryo-miniature plant that has: Epicotyle-shoot above cotyledon Hypocotyl-part of stem below the cotyledon Radicle-primary root, supports seedling

Monocot Germination Seed swells Radicle grows down First internode and epicotyl grows upward New leaves form and food production starts New root system develops Temporary root system ceases to function and dies

Dicot Seeds Seed coat-protection Embryo-miniature plant 2 cotyledones-seed leaves Epicotyl-true leaves Hypocotyl-first stem, pulls seed upward Radicle-forms roots

Dicot Germination Seed swells Radicle grows down Hypocotyl forms arch that breaks soil surface Hypocotyl reaches light and straightens up Cotyledons turn green and make food As new leaves develop, cotyledons dry up and fall off

Seeding

Selection of Seeds: Identify seeds grown locally Check germination ability Purchase from a reliable dealer Chose hybrid varieties for greater vigor, uniformity, and flowering ability Select uniform heavyweight or primed seeds

Improving Germination of Seeds: Sorting Seed quality Weight Heavier seeds tend to grow faster and produce larger plants Primed or enhanced Soaking in salt solutions of KCl or ethyl alcohol Causes growth hormones to become active More uniform, germinate sooner

Germination Medium Soil characteristics Firm Porous Uniform in texture Sterile Free of weeds, insects, and disease organisms

Soil Composition Loam composed of: What is loam? 45 % mineral matter 5 % organic matter 25 % air 25 % water What is loam? Equal parts of sand, silt, and clay

Germination Media: Peat moss Partially decomposed vegetation that has been preserved under water Collected from marshes, bogs or swamps Has high capacity for holding water Sphagnum moss Dehydrated remains of acid bog plants Sterile and lightweight, controls disease and has excellent water-holding capacity Perlite Volcanic origin that expands when heated Improves aeration and drainage of media

Germination Media: Vermiculite Neutral pH High water-holding capacity Jiffy mix Composed of sphagnum moss, peat, fine grade vermiculite, and nutrients To make your own media: Good grade, sterilized topsoil Proper drainage from sand or perlite Peat, moss or vermiculite to add water-holding capacity 1/3 soil, 1/3 drainage material, 1/3 water-holding material Sterilized or pasteurized by heating at 180°F for one-half hour