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.
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2 comments:
sulax
Dear Clare - this sounds like something from Lord of the Rings or an opera plot. May I suggest the following translation?
Phytophthora is the beautiful wife of the Greek tycoon Genius. A bunch of speculators work with the Genius plotting to overthrow the Pathogens, the economically significant supporters of Phytophthora. She is in love with Oomycetes (better known as Walter Mitty). With his sister Oomycota he escapes her by taking a taxi to Phylum in the Kingdom of Stramenophila, leaving her in the Kingdom of Fungi where she listens to classical music. The Fungi fight off Oomycetes who forever after is called Pseudofungi by the people of Fungi.
In Act II Queen Stramenophila, from her cell high above the Chitin, distinguishes Oomycetes far off, separates from her husband Septae and, to defeat Mycelial (who has deployed nuclear weapons), sends her servant Sporangia to Oomycetes with the key to her cell.
Unfortunately, Flagella, the composer, died before he could finish the work though notes for Act III suggest there was the usual hanky panky you get in opera.
David
Wow, in many ways that sounds a lot more exciting than what is really happening. I think this merger of scientific language and literary mastery requires full publication for it to be fully appreciated.
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