David W. Kramer
kramer.8 at osu.edu
Tue Jan 4 10:33:30 EST 2000
This is not my area of speciality so I can't give you references to the
literature on this topic at the moment (I need to leave my office soon) but
I would suggest you do a simple experiment testing the phenomenon that many
fruits produce juices that inhibit the seeds from germinating while still
in the fruit. Why do you think this would be advantageous to the seed?
Would it be advantageous for the seeds to germinate while still in the
fruit? How do seeds get out of the fruit? What is meant by "seed
dispersal" and what is the advantage 1) for each seed and 2) for the parent
plant (especially if it is a perennial)?
You can test this by going to the supermarket and buying some fresh fruits.
I would recommend, for example, the citrus fruits like orange, lemon, lime,
and grapefruit (and there are others). Remove the seeds. Wash half of
them in several changes of water (room temperature) to remove the juice on
the surface and even some that has soaked into the seed. Place them in a
shallow dish with water. Do not cover them completely and do not let them
dry out... ever! You might try covering them with damp paper towels.
Squeeze the juice from the fruit and put the other half of the seeds in the
juice. Keep all other conditions (light, temperature, moisture, etc.) the
same. See which seeds germinate. Keep careful records about what happens
with each type of seed including dates. Calculate the percentage of
germination of each.
You could try this with other fruits. However, many seeds need a cold
period before they will germinate. Their failure to germinate might be due
to the lack of a chilling period instead of to the presence or absence of
the juice. This would more likely be true of plants that grow in temperate
regions rather than tropical regions. Can you explain why this would make
Good luck with your science project! I hope your interest in biology,
especially in plant science, will continue. There are many interesting
career opportunities in plant biology. You might want to explore more
about plants by visiting the web site of the Botanical Society of America
at http://www.botany.org At that site you will find links to many other
intersting web sites with plant information.
By the way, I judge science fairs at district and state levels and I have
one piece of advice on your project: Follow the scientific method
(observation, problem, hypothesis, data gathering and analysis,
conclusions, communication) and keep the experiment very simple. Report
the actual results of your experiment even if they don't seem to support
your hypothesis (prediction) of what you thought would happen. The judges
don't expect you to have discovered something truly new to science but they
do expect you to learn how science works.
>My name is Joushua Green I am in the third grade. I am doing a science
>project on how different types of liquid affect the growth of seeds. Can you
>please help me with my research on this subject? I have gone to the libary
>and looked in the encyclopeadia for part of my research any help you can
>give me would be appreciated.
David W. Kramer, Chair
Botanical Society of America
Asst. Prof. of Evolution, Ecology, and Organismal Biology
Ohio State University at Mansfield
1680 University Drive
Mansfield, OH 44906-1547
Phone: (419) 755-4344 FAX: (419) 755-4367
e-mail: kramer.8 at osu.edu
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