Name _________________

 

EPWS 310 EXAM 2, Fall 2004

 

1.    (2 pts each) Define the following terms:

 

plasmogamy

 

 

haustorium

 

 

ascospore

 

 

oogonium

 

 

homothallic

 

 

plasmodium

 

 

rhizoids

 

 

cleistothecium

 

 

 

2.    a) (3 pts) What environmental conditions favor club root of crucifers and why?

 

 

 

 

b) (3 pts)  What are two methods to control the disease?

 

 

 

 

3.    (4 pts) Explain two ways that Chytridiomycetes differ from Ascomycetes.

 

 

 

 

4.    a)  (3pts) What are two environmental conditions favor Phytophthora root rot of chile and why?

 

 

 

 

b) (3 pts)  What are two methods to control the disease?

 

 

 

 

5.    (4 pts) List 2 ways that Oomycetes differ from Zygomycetes.

 

 

 

 

 

6.    (4 pts) List two ways that Plasmodiophoromycetes and Myxomycetes differ from the other fungal and fungal-like classes discussed in class.

 

 

 

 

 

7.    (14 pts)  You have found a new undescribed powdery mildew on an ornamental shrub.  Although this is a new pathogen, you know the disease cycle for powdery mildew on roses. Outline the disease/life cycle of powdery mildew of rose, including the reproductive phases.  Where in the cycle would this new powdery mildew be most likely to differ from the fungus that infects roses?  What would be possible control strategies for the new disease.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8.    (12 pts) A frantic manager of a local discount store calls you because in an effort to save money they decided to plant their pots of tomatoes and peppers from seed instead of buying plants wholesale.  Although the plants were well-watered, they appeared to die soon after they emerged.  What is the likely disease problem?  What pathogens will you look for?  What will you suggest to the manager for next year to avoid the problem?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9.    (14 pts) Compare the disease, spore types, dissemination, primary inoculum, secondary cycles, overseasoning, and control of the disease cycles of late blight of potato and Rhizopus fruit rot.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10. You have been called to the field to look at mildew on grapes.

 

a)    (4 pts) What are two ways that you can determine if you are looking at powdery mildew or downy mildew?.

 

 

b)    (2 pts)  You decide that it is downy mildew.  How can you microscopically differentiate among the genera of downy mildew to determine which one is present?

 

 

 

c)    (16 pts)  You need to explain the disease to the grower.  Draw the disease cycle of downy mildew, indicating what serves as primary inoculum, secondary inoculum, how it is disseminated, and how it overwinters.  Also show where in the cycle that meiosis, plasmogamy, and karyogamy occur.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(8 pts extra credit)   Outline the disease/life cycle of peach leaf curl.  What is the causal agent (genus and species)?  How can the disease be controlled?