Midterms

While last week turned out to be rather unproductive on the research front due to midterm exams, this week has been jam packed. I have been in the office/lab most of the time and I've started to play around with the brand new weather station equipment, it's all here set up in my office and I've been wiring different sensors into the data logger and I'm learning to program the software to instruct the data logger on how to collect and manipulate the signals into data. I also went through my cultures with Virginia yesterday and they are all going really well, they are growing fast and there were sporangia on one of the species, chlaymidospores on one, and lots of oospores on two of the Phytophthora spp so that is encouraging. I now need to come up with some strategies for continuing with these isolates and a rough experimental design so that I can start to do something with them. I have a meeting with Walt and Nik tomorrow to talk about the weather stations and plan the experiment in more detail.

Progress

At last I have got to doing some practical work. This week I obtained isolates of Phytophthora species from the long term storage in our lab and from another lab on campus also working on Phytophthora spp. and I transfered them onto bigger plates to get them going a little and hopefully begin to play with them and try to get some of them sporulating so that I can move on to inoculate some Rhododendron leaves. I also had a meeting with Nik and Walt about an idea to study leaf wetness sensors so I am going to learn to use the weather station and try to get things set up in my office for that too. Aside from these things it is midterms week so I have had two tests and on Friday I have a lab practical exam for mycology.

Oomycete Biology

Not a lot has happened this week. I have spent a lot of time identifying the mushrooms that I have collected for my mycology class. I am waiting for the lab technicians to grow some of the Phytophthora spp. I asked for from storage onto plates so that I can begin to work with them.

I thought I’d take this opportunity to explain a little of the biology of the organism that I am working with. Phytophthora is the genus and there are a bunch of species within this genus which are economically significant plant pathogens. Phytophthora spp. are Oomycetes (commonly termed the water moulds). ‘Oomycota’ is the taxonomic Phylum, and this is in the Kingdom ‘Stramenophila’, not the Kingdom Fungi as they were once classified. Oomycetes are sometimes termed pseudofungi as they closely resemble Fungi.

The key features which distinguish the oomycetes from the real fungi are their cell walls and their spores. Real fungal cell walls contain chitin, but the oomycete cell walls contain cellulose (as do plant cell walls). The hyphae of pseudofungi are not separated by septae, and the mycelial nucleus is diploid, with two sets of chromosomes. Oomycetes can reproduce both sexually (oospores) and asexually (sporangia, zoospores, chlamydospores). Zoospores are motile with two hair-like flagella propelling the zoospore through liquid, oospores, on the other hand, are non motile. In general sporangia are the survival and dispersal mechanism and zoospores are the infection mechanism.

Federal Holiday

So I went into work at around noon today, after classes this morning only to find the office shut, the doors locked and hardly anyone there and it turns out that it is Columbus day which means a bunch of people skip work for the day, but schools are still in session. Well, Nik was still in his office so I was able to talk to him and we discussed a bit about the directions of my research and the possibilities for the content of my thesis. He suggests that I should plan for between 3 and 6 chapters and that I should treat each chapter like a paper with the potential for publication. He also came up with a new idea about doing a study on the differences between various leaf wetness sensors which could result in a methods paper publication which has a guaranteed high citation rate and would be a good starter project for me to get me familiar with the weather station equipment and the statistical tools used in epidemiological studies.

Aside from this I am still working on identifying the isolates I am going to work with initially and then getting them growing on plates so that I can actually begin some detached leaf inoculations and stuff.

And one other thing - I just added a new link to my photography page which at the moment only has some photos from the work I did at Rothamsted this summer, but there will be more to come, including microscopy images and specimens from my mycology collection for a class I am taking this term.