1 / 15

Seed Germination

Seed Germination. Processes and Requirements. Germination. What is germination? I have used this word before in class It is when the first embryonic root emerges from the seed coat Germination is a process that begins only when certain conditions are met. Germination.

havily
Download Presentation

Seed Germination

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Seed Germination Processes and Requirements

  2. Germination • What is germination? • I have used this word before in class • It is when the first embryonic root emerges from the seed coat • Germination is a process that begins only when certain conditions are met

  3. Germination • Seeds from some plants will germinate as soon as they are released • Others go dormant (a type of hibernation) • They remain dormant until proper conditions are met • What do you think some of those conditions are?

  4. Types of Dormancy • Stratification • Triggered by temperature • Must go through a period of cold • And then warm up • Scarification • Triggered by break-down of the seed coat • What are some ways that a hard seed coat could be broken down?

  5. Stages of Germination • # 1 – Imbibition • Absorption of water • Usually dormant seeds have 5-10% moisture content • At proper conditions water is imbibed very quickly • What does this do to the seed? • It swells • Becomes turgid

  6. Stages of Germination • # 2 – metabolic activity surges • Proteins are made • Enzymes are produced • Amylase – converts starch to sugar • Protease – breaks down stored proteins into amino acids • Sugars and amino acids are sent to meristems • That is where growth takes place • Tips of the root and shoot

  7. Stages of Germination • #3 – metabolic processes increase • Swelling cells break seed coat • Root tip emerges downward • Stem shoot grows upward • Shoot begins photosynthesis • Root begins absorbing water and nutrients

  8. Conditions for Germination • Conditions have to be right for the new plant to survive • They include: • Water • Air • Temperatures • Light/Darkness

  9. Conditions for Germination • Water triggers the process • How much moisture is usually in the seed? • Oxygen must be present for the seed to germinate • It is needed for cellular respiration • Converts stored food into energy

  10. Conditions for Germination • Temperature • Some seeds can begin germinating at as low as 32°F or as high as 105°F • Optimum Temperature is usually between 65°F and 80°F • Temperature influences metabolic activity • Usually faster at higher temps and slower at lower temps

  11. Conditions for Germination • To begin germination: • Some seeds actually need light • Others need darkness • Light sensitive seeds have a photoreceptor pigment in their seed coat • Called Phytochrome • It sends a message to the seed to begin or stop germination

  12. Seed Quality • Is seed quality important? • Why • If you buy a bag of seeds to plant, how many do you want to grow? • Good seeds make good plants

  13. Seed Quality • Defined by two things: • Viability • Ability of seeds to germinate under optimal conditions • Vigor • Ability of seeds to germinate under different conditions and still produce healthy plants

  14. Seed Quality • Seed producers test seeds for germination rates • These rates are printed on the label of the seeds you buy • How do they perform the test?

  15. Seed Quality • What do you do with seeds until they are sold and planted? • Store them • The goal is to maintain viability and vigor while seeds are in storage • What is the best way to store seeds? • Cool temperatures • 40° is usually good • Low humidity • About 15%

More Related