Plant Physiology (Biology 327)  - Dr. Stephen G. Saupe;  College of St. Benedict/ St. John's University;  Biology Department; Collegeville, MN  56321; (320) 363 - 2782; (320) 363 - 3202, fax;    ssaupe@csbsju.edu

Germination Rates & Percentages

Objectives:  The purpose of this lab experience is to provide an opportunity to:

1. measure seed germination percentage and rate
2. determine the impact of age on seed germination.

Introduction:
        Germination percentage is an estimate of the viability of a population of seeds.  The equation to calculate germination percentage is:  GP = seeds germinated/total seeds x 100 .  The germination rate provides an measure of the time course of seed germination.  Germination rate is determined by calculating the GP at different time intervals after planting and then plotting these data. 

Methods:    

1. Obtain a petri dish and filter paper.  
2. Select a seed source and record the name in Table 1.
3. Count out 50 seeds (fewer if large seeds).  Soak them in water for an hour.   
4. Spread the seeds on a layer of filter paper in the dish
5. Moisten the paper with enough water so that the seeds just barely begin to float (about 10 ml).
6. Put on the lid and place the dish in the dark.
7. Record the number of seeds that germinate daily.  Record your data in Table 1.  Remove the seeds as they germinate.
8. Complete Table 1.  

Results:

Assignment:

1. On a separate sheet, complete Table 1.
2. Make graphs plotting:  Cumulative percent germination vs. day; and Percent germination during time interval vs. day   
3. Write a brief conclusion/summary of your observations.