Induction
of Apothecia Formation and Ascospore Collection of Sclerotinia sclerotiorum
W. A. Gutierrez, H. D. Shew, and T. A. Melton
The
primary source of inoculum of Sclerotinia sclerotiorum can either
be sclerotia (myceliogenic germination) or ascospores (released from apothecia
by the carpogenic germination of sclerotia).
One of the important steps in the study of the pathogenicity of this fungus
is the production of ascospores to simulate natural infection that occurs
in the field.
Sclerotia Production
Sclerotia
originated from cultures of S. sclerotiorum grown on
carrot is used for production of ascospores.
- Infest 30g of sterile carrot disks/125ml flask with a mycelial disk
of a Sclerotinia isolate.
- Incubate flask at room temperature.
- Harvest sclerotia after 15 to 20 days of incubation in sieves with 2
mm and 0.5 mm opening in running tap water, and let them dry for 48 hours.
Apothecia Induction
- Fill 120
ml. jar with 40 cc of dry sand and 10 cc of deionized water.
- Sterilize them for 30 min. (15 at 120 C).
- Disinfest sclerotia in 20% sodium hypochlorite solution for 1 min.,
then rinse with sterile water and allow to dry.
- Transfer 5 to 10 disinfested sclerotia into the sterile jar.
- Set jar at 4 C in the dark for 1 month, them place the jar in a 12 C growth
chamber in the dark until the stipe is observed. When the stipe is 5 mm
long (2 to 4 weeks), transfer the jars to a 16 C growth chamber with
a 12 hour dark and light period, until apothecia are fully mature (2 to
6 weeks).
Ascospore Collection
- Mature
apothecia are set in a growth chamber at 21 C and a 12 hour period of
dark and light.
- Ascospores are collected using the Millipore membrane attached to a
vacuum system.
- Store millipore membrane at 4 C in a dessicator.
Back to:
Collar
Rot in Tobacco Greenhouses
Plant Disease Information
Notes Home Page
North Carolina Insect
Notes
North
Carolina Agricultural Chemicals Manual
CALS Home Page
NCCES Home Page
NCARS
Home Page
For assistance with a specific problem, contact your local North Carolina Cooperative Extension Service
North
Carolina Cooperative Extension Service
Distributed in furtherance of the Acts of Congress
of May 8 and June 30, 1914. Employment and program opportunities are offered
to all people regardless of race, color, national origin, sex, age, or
disability. North Carolina State University at Raleigh, North Carolina
A&T State University, U.S. Department of Agriculture, and local governments
cooperating.
Revised July 2001 by Plant Disease and Insect Clinic