Plant Physiology

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

Light and Seed Germination

Introduction
Some seeds require light for germination. In this exercise we will test to see if your seeds have a light requirement. We will set this up in the form of a typical experiment.

Question: Do our seeds have a light requirement for germination?

Hypothesis: My seeds do not require light.

Predictions: If my seeds do not require light, then the germination percentage for the seeds planted in the light and dark should be the same.

Protocol:

Obtain two petri dishes. Line each with paper towels and moisten.
Place 50 seeds in each dish.
Wrap one dish in aluminum foil. Label both dishes with your name and date and then place them in the light.
When the seeds in the light have finished germinating, open the foil and record the number of seeds that germinated in Table 1.
Calculate the germination percent for the seeds in both the light and the dark.

Results:

Table 1. Germination of ____________________ seeds after _________ days in a petri dish lined with filter paper and moistened with water.
Treatment	Total Seeds	Seeds Germinated	Seeds not germinated	% Germination
Light
Dark

Statistical Test:
It is likely that we will need to perform a statistical test to determine if our germination rates are significantly different. We will use a Chi square 2 x 2 contingency table test. This is available through the Concepts of Biology web site. We will discuss it in class.

Null hypothesis (Ho):
x² =
p =

Conclusion:

What do you conclude about the effect of light on germination?