• Science Desk >> ATW
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Bananas
There is an impending threat that may wipe out bananas all over the
world. The black sigatoka fungus is beginning to take a toll on banana
crops. The fungus has affected crops from Florida to South America and
Africa. Why are bananas such easy victims? Well, the next time you open
a banana...look for seeds.
Unless you're eating a plaintain, a cousin of the banana you won't
find any. Plantains are loaded with seeds but bananas reproduce without
flowers and seeds. They grow a new tree from a runner. Now a good example
of a runner is this spider plant. In this above ground one, right here.
Now if this were a banana plant that runner would be underground and
this would be the new banana tree.
It shoots off the parent plant and goes on to make a brand new, identical
plant. this works fine as long as nothing threatens the parent plant.
But when something new and nasty comes along, like black sigatoka, the
new plant will only be as weak or as strong as its parent plant.
This is a perfect example of the natural battle between predator and
prey. Something you may know as survival of the fittest. I want you
to think about this...in a typical predator/prey situation, if a newer
or faster or stronger predator comes along, only the prey that is skillfull
in escape will survive. This, of course, selects for the still, faster,
still stronger predator which selects for the stronger and faster prey
and it goes on and on.
Well, in this case the fungus is the predator and the banana is the
prey and unfortunately the bananas are so similar to each other, that
if one lacks an adaptation to protect itself from the fungus, they all
do. Its an evolutionary dilemna that could lead to extinction.
Now, the world's hope for a better banana rest with the International
Network for the improvement of the banana and plantain. Otherwise known
as INIBAP. They are hard at work trying to produce a new banana that
may be resistant to black sigatoka.
You can learn more about this issue on the web and there is an experiment
on fungus growing available for you and your teachers at atwonline.org.
That's it from the Science Desk.
More Information
EXPERIMENT
http://www.fofweb.com/Onfiles/SEOF/Junior_Science_Experiments/4-11.pdf
The Free
Acrobat Reader must be installed to read the experiment in PDF
(Portable Document Format). Download
Acrobat Reader from Adobe.com
HISTORY OF THE BANANA AND OTHER INTERESTING BANANA INFO:
http://www.banana.com/
MORE ON BANANA SURVIVAL:
http://news.bbc.co.uk/2/hi/science/nature/2664373.stm
INIBAP HOMEPAGE:
www.inibap.org
BANANA RECIPES:
http://southernfood.about.com/cs/bananarecipes/
© 2004 WXXI-TV/ Assignment: The World.
All Rights Reserved.
