As you all know, we are now many weeks into our plant unit, during which time we’ve studied seeds, some of the substances found inside of seeds (e.g., starch and embryos), seed germination, seed dispersal (remember the exploding balsam seed pods and the squirting cucumbers in the BBC video?) and, more recently, the growth of seeds into small seedlings. Our 6 day old seedlings, which we are raising in our classroom growth chamber, can be seen in the photograph at left.
I hope that all of you now understand that most seeds require only a few things in order to successfully germinate: water, proper temperature, oxygen gas, and an internal source of energy (e.g., starch, which is a long chain of sugars).
Well, earlier tonight, as I was cutting open a tomato to put on a sandwich for dinner, I was surprised to see the scene now visible in the center of the picture below. I hope you can see them, but if you look closely (at least as far as I can tell) there are two seeds inside of the tomato that had tried to germinate!
The more I think about it, the more this makes sense…first, I never keep my tomatoes inside of the refrigerator because the cooler temperatures help take away the wonderful taste of a ripe tomato. So, this tomato was probably able to provide its seeds with the proper temperature range needed to germinate. Second, as we all know from experience, there is plenty of water to be found inside of the tomato surrounding the tomato seeds. Third, these tomato seeds must have been given a source of internal energy by the ‘mother’ plant from which this tomato was taken. Most likely, this source of energy took the form of food (e.g., starch) . And finally, if in fact the seeds did germinate (which appears to be the case) somehow the seeds must have been able to access oxygen gas while inside of the tomato. If not, they wouldn’t have germinated, right?
All this is to say that plants–even something as common as a ripe tomato–are full of surprises and, as I hope you are discovering during our Wisconsin Fast Plant unit, plants are capable of some truly amazing feats.