Gigaspora rosea appears to favor an aerobic environment for sporulation, here in and on vermiculite. How many spores can you identify in this photograph?
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- Gigaspora rosea prefers to place its spores in vermiculite
- Surprising survival: 46 days in the refrigerator
G. rosea prefers vermiculite
Gigaspora rosea has a reputation for being difficult to cultivate axenically, with cultures typically “dying out” after 2 or 3 generations. In Petri dishes with polymer, in symbiosis with Plantago lanceolata, the fifth generation was reached without any sign of loss of vitality.
This species appears to prefer vermiculite over polymer for sporulation. It never produces spores inside the polymer grains. Spores are found in modest quantities on the polymer grains, occasionally more on the Petri dish walls and the dividing membrane, and abundantly in the vermiculite (by sieving). These observations suggest a preference for an aerobic environment.
46-day survival in the refrigerator
Plantago lanceolata plants colonized by G. rosea survived a 46-day stay in the dark in a refrigerator at 4°C.
An extended absence from the lab, with no one available to monitor the cultures, led to placing four Petri dishes of well-colonized P. lanceolata by Gigaspora rosea in a sealed freezer bag in the refrigerator. The hope was that the colonized roots could be used to restart the cultures upon return, even if the plants didn’t survive. These plants had been in culture for 6 months.
Against all odds, all four plants survived and resumed growth as soon as they were placed back under LED lighting. The polymer was then replaced with fresh, uncolonized polymer to check whether the fungus was still active. An observation made 46 days after this replacement confirmed that all four plants were healthy, with normal foliage. Two dishes showed a few new hyphae in the fresh polymer. In the other two, no hyphae were observed on the polymer side, and no circulation was detectable in the numerous (old) hyphae on the vermiculite side.
