Sexual Plant Propagation

1. Sexual Plant Propagation

2. Definition • Propagation-to reproduce or increase in number

3. 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

4. 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**

5. 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

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

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

8. 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

9. 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

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

11. 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

12. Seeding

13. 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

14. 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

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

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

17. 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

18. 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