Last Saturday I spent some time looking at slides and cultures of the two Phytophthora isolates I am working with. I did not get any good pictures with the PaxCam set up, which was disappointing. The structures I was looking for were just too small for a dissecting scope.
Under a traditional microscope I managed to see oogonia, oospores, and what I think were sporangia. I took some photos using a rather low tech method (using my Nikon D40 to shoot through the eyepiece of the scope). Here is a representative:
Phytophthora cactorum under the microscope.
The Phytophthora cactorum isolate was relatively easy to understand. The P. drechsleri was not as clear. I need to spend more time looking at it.
In the picture above all the thread-like stuff is hyphae. Most of the round things are oogonia, which are filled with small oospores. I think a few of the rounded shapes are sporangia, but I’m not sure of this. In the picture below the lighter rounded shape in the center is what I think a sporangium looks like. So there are five oogonia and one sporangium in the picture if I am interpreting it correctly.
Phytophthora cactorum oogonia
I’ll be spending more time making slides and peering at cultures over the next few days.
