Introduction to Plant Reproduction

1. Introduction to Plant Reproduction

2. Objectives: Distinguish between asexual and sexual reproduction of plants; Discuss importance of both types of reproduction in plants; Identify major parts of seeds; Describe process of seed germination.

3. Define Propagation • Propagation • The reproduction of plants either sexually or asexually.

4. Asexual vs. Sexual Reproduction • Asexual reproduction involves ONE living organism. • Sexual reproduction involves TWO living organisms.*Male and Female* Can be on one plant.

5. Define sexual reproduction • Sexual Reproduction: • The union of the female and male sex cells to produce a seed (embryo). • Ovule: female sex cell. • Pollen: male sex cell. • Embryo (seed-germ): an immature plant. • *Sexual reproduction involves the creation of a genetically new individual.

6. Define asexual reproduction • Asexual Reproduction: • The reproduction of a plant without the uniting of a pollen and ovule. • Asexual reproduction is often referred to as vegetative propagation since no seed is involved in the formation of the new plant. • It is known as a clone. • Leaves, stems or roots may be used to grow a new plant. • *Produces a genetically identical plant.

7. BRAINSTORM • Group A: Brainstorm benefits of asexual reproduction of plants (i.e. vegetative propagation) • Group B: Brainstorm benefits of sexual reproduction of plants (i.e. seeds)

8. Benefits of Asexual Reproduction (Vegetative Propagation) • True traits of the parents • Maintains genetic purity with • 100% replication of parent plant. • No seed • Some plants do not produce a seed or the seeds are too small to work with. • Accelerates the time it takes to get a new plant to the market • Traditionally, it would take up to 40 years to get a new plant to the general public; however, micropropagation can yield marketable levels of plants within 8 to 12 years.

9. Benefits of Sexual Reproduction • Genetically new individual created • Hybrid created • Potential to improve crop traits • Seed can be stored

10. Types of seeds. • Monocots: • Seeds with one seed leaf • Dicots • Seeds with 2 seed leaves or 2 cotyledons

11. Monocots

12. Dicot

13. Parts of a Seed • Embryo Plant = will become seedling plant • Cotelydon(s) • Primary Root (Radicle) • Embryonic (seed) leaves • Endosperm = stored food • Seed coat = protective shell

14. Label a Lima Bean • Cut: • Carefully cut the lima bean in half; • Place the halves on the paper plate. • Label: • Cut and label tags from the sticky-notes; • Stick each label on its own pin; • Place the labeled pins in the correct part of the seed.

15. Pollination, Fertilization and Germination • Pollination • The transfer of pollen from an anther to a stigma of a flower of the same species. • Fertilization • The union of the pollen and ovule cells. • Germination • The sprouting of a seed.

16. Germination • Process by which an embryo plant inside the seed changes into a developing seedling. • Germination is the end of the period of dormancy • Favorable conditions are present for the growth and development of the seedling plant…so it sprouts and starts to grow!

17. Seed Germination Test • The germination rate is a measure of viable seed, or the percentage of seeds planted that sprout. To calculate: The number of live seeds divided by the number of seeds planted equals the germination rate.