Change of Goals

Well I know I've not been keeping up on this blog very regularly but I'm going to post an update. I have been thinking long and hard about my career goals and I have come to the decision that I do not need a Phd to do what I want to do after graduate school. After a very stressful year I have decided that I don't want to get a Phd but I will write up my thesis for a masters and I hope to defend it this coming spring.

Long time no post

I've just built some irrigation in a hoop house at the farm. Here are two photos of the trial I have running currently to test the set up. I'm hoping the central plant (inoculated with warm season phytophthora spp) will spread their infection to the surrounding healthy Rhodies.

Southern Red spider mites

More mites! Since southern red spidermites were found on Pieris plants in the chamber I had to toss all those plants and order more. The chamber has since been completely cleaned out and decontaminated.

mite outbreak

We found spider mites which feed on cultures in some phytophthora plates so we had to throw out a lot of cultures and decontaminate the incubators. This has set things back a little bit in the lab. I have instead been getting going with some data analysis of my field experiments which have been running for a year now. It's nice to see the seasonal differences in the species of phytophthora which do best at different temperatures. I now have more ideas about what to move forward with and I can repeat a second year of data to gain more confidence in my results.

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Koch's Postulates

Activation of isolates was successful with almost all isolates so I am now able to move on to carry out Kochs postulates with them. The aim of Koch's postulates is to confirm a diagnosis that a particular suspected organism is causing the observed disease. The steps were first described by Robert Koch in 1882 and later added to by Erwin F Smith in 1905. The steps are as follows:

1. determine the suspected pathogen is consistently associated with the disease
2. isolate the suspected pathogen from the diseased plant and grow it in pure culture on artificial media and describe it.
3. Inoculate the isolated organism onto a healthy plant of the same species to see if it causes the same disease symptoms.
4. Re-culture the pathogen and determine that it is the same as the original isolate.

Steps one and two have already been completed so I am now going to work on steps 3 and 4.

Isolate activation

I am hoping to 'activate' some isolates by inoculating them into rhododendrons and then re-isolating them from the plant after infection has occurred in an attempt to remind the isolates how to be virulent. Some times we have isolates that have been maintained for so long in culture that they start to behave strangely or they stop sporulating for example. This is a technique to re-activate them before using them in experiments.