1. Plant Science CSES 1203 Dr. Skulman
Week I
Seed Germination

2. Seed Germination
Is germination the beginning of a plant’s life cycle or the end or is it both beginning and end?
Annual seed bearing plants do the following things according to the calendar:
Spring-seed is planted, germination follows,
Summer-plants grow, flower, and form seed,
Fall-seed ripens, is harvested or falls from plant,
Winter-seed is dormant or in storage,
Spring-seed is planted, yearly cycle is complete.

3. Taxonomy Kingdom-All plants (500,000 species)
Division-Seed producers (spermatophyta), and non-seed producers
Classes :
* gymnosperm (naked seed)
* angiosperm (seed produced in an ovary) normal flower.
We will examine angiosperm germination

4. Monocot (hypogeal) germination

5. Dicot (epigeal) germination

7. Requirements for germination
Proper temperature, varies by species
Water
Oxygen
Light (not for all species, some grasses)

8. Seed dormancy Resting period for seed between harvest and planting
Can last from several weeks to many years
Dormancy delays germination until conditions become favorable
Soybeans in Arkansas
Harvested in Fall (followed by winter-unfavorable)
Planted in Spring (conditions now favorable)

9. Role of water in germination
Water absorbed by seed from soil
Water causes seed to swell
Releases hormones in seed
Hormones stimulate enzymes to break down stored starch to glucose (C6H1206)
Glucose is a simple plant sugar that is used to provide energy for germination

10. Roles of Temperature and Oxygen in Germination
Oxygen- all living cells require oxygen for respiration; plant cells of root, stem and leaves are actively growing
Temperature- physiological reactions within plants are influenced by temperature; too high or too low stops reactions in plants

11. Moncots and dicots Dicots: Monocots:
Examples, oak trees, beans, clover, shrubs
Leaves have netted venation
Taproot system
Monocots:
Examples-corn, grass, wheat, rice, cattails
Long, slender leaves with parallel veins
Fibrous root system

12. Other comparisons between monocot and dicot plants
Monocot Leaves
Dicot Leaves

13. Class Seed Germination Discussion Questions:
As a farmer, why would you want seed to germinate all at the same time?
Why do farmers/gardeners till their land before planting seed?
In the spring some farmers will apply herbicides to the soil for weed control.
Why would extended herbicidal activity be an advantage?

14. What foods are derived from germinated seed?
1. Sprouts such as Mung bean or “alfalfa” sprouts

15. 2. Barley grain is used to make beer and wiskey
2. Barley grain is used to make beer and wiskey. However, the grain cannot be used
directly, but must first be modified. What is this “modification”?
Malting – a process where the grain is initially germinated and then oven dried
to different stages of color.

16. The End

18. Monocot (hypogeal) germination