6. Chromista Flashcards
What are the three main characteristics of Chromista?
- Are pseudo fungi which have filamentous mycelia, multinucleate, non-septate hyphae
- Cell walls contain glucans and cellulose but NO chitin
- Can reproduce sexually or asexually
What is another way of calling a non-spetate hyphae?
coenocytic hyphae
What is the name of the asexual Chromista spores?
zoospores
Where are zoospores produces?
in the sporangia or sporangia on sporangiophores
What is the name of the sexual Chromista spores?
oogonium + antheridium = zygote –> oospore
What are the two main families of chromista important pathogens?
- Phythiacea
2. Peronosporaceae
What are the Phylum, Class, and Order of Phythiacea and Peronosporaceae?
Phylum : Oomycota
Class : Oomycetes
Order : Peronosporales
Give an example of an important chromista pathogen in the Phythiacea family.
- Pythium ultimum
- Phytophthora infestans
Give an example of an important chromista pathogen in the Peronosporaceae family.
- Plasmopara viticola
- Bremia Lactucae
- Peronospora sp.
Do sporangiophores have indeterminate growth on Pythiaceae organisms or Peronosporaceae organisms?
Phythiaceae
Do sporangiophores have determinate growth on Pythiaceae organisms or Peronosporaceae organisms?
Peronosporaceae
What diseases is Pythium responsible for?
damping off and root rots
What diseases is Phytophthora infestans responsible for?
- blight of leaves
- blight of young stems
- Tubers: sunken dry rot type lesions; inside brownish discoloration; rotting
- Tomatoes: dvp. soft rot
What are the signs of Phytophthora infestans papthogen?
under humid conditions on the surface of leaves and fruits, white mycelia and sporangiophores develop–> fluffy or downy growth BUT NOT downy mildew
