EPWS 310 EXAM 2, 2001
1. (2 pts each) Define the following terms:
2. a) (4 pts) What environmental conditions favor Phytopthora root rot of chile and why?
b) (4 pts) How does the peach leaf curl fungus differ from other plant pathogenic Ascomycetes?
c) (4 pts) What are two structures that endomycorrhizae produce that other Zygomycetes which cause post harvest rots lack?
d) (6 pts) How can Zygomycete post harvest rots be controlled? Name a fungal genera of this class that induces disease?
e) (4 pts) What are two methods to manage Phytophthora crown rot of fruit trees?
3. (12 pts) make a simple dichotomous key (or flow chart) to differentiate the Myxomycetes, Chytridiomycetes, Oomycetes, Zygomycetes, and Ascomycetes. Explain what characters differentiate the classes at each step or junction..
4. (18 pts) Compare and contrast Pythium root rot of vegetables with downy mildew of grape, including colonization, disease, overseasoning structures, asexual spore formation, environmental effects, and control.
5. (12 pts) What is the nuclear state of Oomycete and Zygomycete mycelia and when does plasmogamy, karyogamy, and meiosis occur?
6. (22 pts) Compare and contrast the current life/disease cycle of Phytophthora infestans causing late blight of potato with that of powdery mildew of roses caused by Sphaerotheca pannosa. Make sure to include both reproductive phases as well as dissemination and overseasoning, primary inoculum, secondary cycles, and control.
(6 pts extra credit) Outline the disease/life cycle of the chile root rot. What is the genus/species of the causal agent?