Those fascinating observations from pollen grain germination in the Brahma Kamalam drew me irresistibly towards flowers of other plants. Recently I have been watching educational videos as now I am planning to create videos for school students using Foldscope images. In the biology videos for Classes 11 & 12 I noticed that Vinca rosea (Periwinkle) is commonly used to show pollen germination.
I decided to try that with the medium that we had earlier used to observe the Brahma Kamalam’s pollen. I took a drop of solution on a glass slide and dusted the pollen onto it.
Within just a few minutes the pollen started germinating.
The foldscope was attached to my iPad and I quickly pressed the time lapse option. I stopped after 20 minutes and replayed the video. I kind of lost the full field of view but you can see towards the end that two of the pollen tubes suddenly burst and the plasma pours out.
I then scanned the slide and found many pollen grains interlocked with pollen tubes. It looks like cent percent germination.
Next I took pollen from a just-bloomed flower, attached a Foldscope to my iPad and left it for an hour on time-lapse. Here I saw various events: plasmolysed pollen, burst out pollen and germinating pollen. Notice that the fast-growing pollen tube near the top is connected to the most hectic activity inside the pollen grain!
Next I turned to the older flowers and recorded for one hour. Hurray! Almost all the pollen grains germinated and the plasma movement was clear too.
It is my first perfect time-lapse video. Watch and enjoy!
I continued my observations with Mirabilis Jalapa flower (also known as the four o’clock flower).
This is the largest pollen grain I have observed. Again I put the pollen into the medium. Before starting the time lapse I saw that some pollen grains were open.
This time too, I recorded an hour’s footage as a time-lapse.
No change, not even the slightest movement in the protoplasm. Is this medium not working on this plant pollen? Or is the pollen grain not viable?
The next victim in my hand was Zephyranthes candida (rain lily). Usually these flowers open at night and release pollen at dawn. I collected this flower at noon and noticed its anthers were intact.
I tore the anther and dusted pollen into the medium. The pollen grains were oblong in shape. I took a time-lapse video for an hour. Here we can see slight movement in the protoplasm but no indication of germination. Is this because of late anthesis? I should have waited to collect the pollen at their natural time of release.
My next victim was yet another sacred plant, Ocimum tenuiflorum (Krishna tulsi) or holy basil. It has small purple flowers with yellow anthers, and the smallest pollen grains I have ever observed. This image shows the hexacolpate pollen.
Again I tried a time-lapse video for one hour. It shows the tiny grains of pollen sitting around a large anther. I noticed minute movement in the pollen grains but not much change.
From all these observations I came to the conclusion that this medium had some effect on Epiphyllum oxypetalum (not clear if it was germination) and Vinca rosea (definitely germination). In pollen germination concentration of medium and temperature are important factors. Maybe the change in proportions of calcium, boron, sucrose and magnesium influences the germination of pollen.
There are so many possibilities for studying the germination of pollen of different plants. Slowly this Foldscope is dragging me towards research into something that is unknown to me.