Tag Archives: tobacco seeds
Growth of tobacco seeds in low concentrations of deuterium
Growth of Tobacco Seeds in Heavy Water
Tobacco Seed Growth Rates
I got some awesome new data to show. The first is the compilation of all the Repeating Crumley experiments. And the second is some new data that I’ve been meaning to create and now have with the help of Koch.
The data above is the compilation of all the RC data. Each trial had different water types, but I combined the samples that were the same in every set (DDW, DI water, 33% D2O, 66% D2O, and 99% D2O). Steve adapted his R-code that applies binomial confidence intervals to a data set and used it on this data. If that makes no sense, then just know that the dotted lines are the most probable range of germination rates. For instance, in 66% D2O there is a ~70% likelihood that seeds will germinate at a rate within the dotted yellow lines.
Now it’s time for some brand new data:
Here we went through the pictures from Trial 5 and compared the growth rates of the roots. We calculated the lengths of various seeds in each image and tracked the changes from image to image. We chose DI, DDW, and 1% D2O, because the D2O concentrations are relatively similar and because we wanted to test a hypothesis from a while ago. It’s interesting that the seeds in DDW and D2O grow at the same rate, while seeds in DI water grow at roughly half the speed.
RCD: Day 36
- 2mo old D2O sample
This will be the final data point for this experiment. Looks like seeds don’t grow in 99% D2O as Lewis reported, but Crumley argued against.
RCD: Day 28
- 2 month old d2o sample
Still nothing growing and the old sample that had one sprout stopped growing as well, which leads me to believe it started growing a long time ago, possibly while still in the package and not in D2O, and I just never noticed.
RCD: Day 22
- 2 month old D2O sample
It should be noted that the annual spring cooling system maintenance is occurring as I post this. That means that the lab is excurciatingly warm right now and this may negatively impact the seed growth (which shouldn’t happen anyways).
































