PLANT CULTURE
|
Container.......... |
Bench or tub with adequate depth for root
development (6-8 inches) |
| Media............... |
Soil Mix (1:2:1; Top soil: sand:
sphagnum/perlite) adequate lime and fertilizer (0:24:24) |
|
Temp/Light........ |
24° to 30°C.; 16+ hour daylength |
|
No. of Plants .... |
50-60 per replication |
| No.
of Reps....... |
4 replications |
| Other................ |
Inoculate with Rhizobium
meliloti |
INOCULUM CULTURE
|
Source.............. |
Infected roots |
| Storage............. |
CSilica gel crystals or agar
cultures |
| Temperature......
|
4°-10° C |
| Storage
Life....... |
1 to 2 years |
INOCULATION PROCEDURE
|
Age of Plant...... |
8 weeks old |
|
Type of Inoc...... |
Microconidia in water suspension |
|
Inoc. Culture...... |
Potato Dextrose Broth; inoculate
sterile broth with PDA plugs and incubate on a shaker for
4 days at 20°-24°C. |
|
Concentration..... |
1 X 106 spores per ml |
|
Method............... |
Clip and bare root soak |
|
Time of Inoc....... |
20 min at 24°C or 12 hours at 16°C |
INCUBATION
|
Location............. |
Greenhouse: transplanted into
benches or tubs |
|
Temp/Light........ |
28° - 32° C; 16 hour daylength |
|
Culture.............. |
Provide an arid environment to
facilitate symptoms. Clip top growth twice at 5-6 week
intervals (at bud or bloom) maintain good growth and
control insect pests; fertilize (0-24-24) after each
clipping |
|
Spacing............. |
2.5 cm between plants and 6 cm between
rows |
|
Age of Rating..... |
12-14 weeks after transplanting |
RATING
Plants are removed from benches and cross sections of
roots are rated
Resistant.......Symptomless root or discrete dark specks in
the stele of the root
Susceptible....Any dark discoloration in root with an arc
or ring pattern; severe necrosis of entire root; dead
plant
CHECK CULTIVARS
| |
Approximate Expected
Resistance* |
Acceptable Range (%) |
| Resistant |
|
|
| Agate** |
45 |
35-55 |
| Moapa69 |
70 |
60-80 |
| Susceptible |
|
|
| MNGN-1** |
4 |
0-8 |
*Controlled environment evaluations can be more severe
than field evaluations (check varieties may have a lower
resistance when compared to field results)
SOURCE OF INOCULUM
AND EXPERTISE
Name..........Landon Rhodes
Address......Dept. Plant Pathology
201 Kottmann Hall
Ohio State Univ.
202I Coffey Road
Columbus, OH 43210
REFERENCES
See Fusarium Wilt field protocol In: STCAC
|