18.104.22.168. Mating test
single isolate is obtained, the mating type can be determined using a sexual
compatibility test. We recommend that the two reference strains (AFSEF 7405 and
ARSEF 7406) be used in the mating tests.
- Cut agar plugs from the border of well growing isolates
- Place the plugs of the new isolate between agar plugs of the two reference strains with a distance of approximately 4 cm
- Incubate the plate in darkness at 30-34 °C
- After 5-7 days the presence of dark spore cysts (Fig. 5) normally can be observed as a black zone where hyphae of two strains with opposite mating types meet, indicating successful reproduction
- If the test isolates are sexually compatible with the
reference + strain, the other is the – mating type, or vice versa
On a standard
agar plate (diameter 9 cm) 4 new isolates can be tested simultaneously (Fig.
Fig. 5. Ascosphaera apis mating test and production of inoculums. A. Mating test with four isolates of unknown mating types. Unknown 1 mates with ARSEF 7405 (+) and therefore harbours the opposite mating type (-). B. Production of inoculums between two isolates of opposite mating types. Fruiting bodies with spores inside are formed where the hyphae meet (black zone). Photo: A B Jensen.