Stomatal measurements and ploidy

A while back Harry asked “I am particularily interested in the simple stomata experiment. Does anyone have any experience with it and roses?” and the conversation went in a direction of how to calibrate a microscope.

A paper I just found in American Journal of Botany 93(3) 412-425 by S. Joly et al titled “Polyploidy and hybridization in roses east of the Rocky Mountains” does include measurement of stomatal guard cells to differentiate between diploid and tetraploid individuals within a single indigenous american rose specie.

It also references Lewis’s dissertation’s publication which detailed how the test was done and summarizes his methodology.

Once I have leaves again, I’ll do a quick test on my Europeana and its sport. With this measure, I’ll use a micrometer eyepiece at a specific magnification. What the real distance between two black lines is …won’t matter. I’ll just assign a letter to it (or name it for a cat) and do the measurements. As long as I keep the zoom magnification the same, a tick mark on the scope, the measurements will be comparable.

Google search also lists a lot of papers for other genera that use this method of determining ploidy.

Hi Ann, From the data I have taken stomatal size has been very useful with a good control- such as your Europeana and sport, the diploid polyanthas from which I tried to generate tetraploids…

However, in general as I looked at mixed rose germplasm there seems to be such a wide variability it is difficult to use for general ploidy prediction- unlike pollen. This seems to be the case especially for modern roses with such diverse backgrounds. As I read more it seems like the number of stomates in a given surface area and their size can differ for what is optimum based also on climate (temp and humidity…), so the variability from adaptation to different climatic conditions seems to add variability in addition to ploidy and make it a difficult trait to use for general use when we do not have good controls.

I’m excited to learn what you find with your Europeanan sport.