play an important role in the survival of plants on poor soils. Planting seeds
into lunar soil at a lunar colony will be a challenge for seeds of any plant.
The seeds will need a special microbial “tool kit” that will help them germinate
and the young seedlings establish themselves. In this study, seeds of the prickly
pear cactus, Opuntia ficus-indica, were chosen to examine the presence of
fungus spores in the soil, inside the seeds and after germination in the
rhizosphere, roots and other tissues of the young seedlings. The nutrient poor
lunar regolith simulant JSC-1A was used as autoclaved or untreated growth
medium. The mycorrhizal fungus Trichoderma
viride was predominantly identified on the roots of new seedlings. This
fungus also demonstrated the strongest effect on the germination rate of the
seeds in comparison with other fungi isolated from the rhizosphere of Opuntia plants. T. viride was not detected within seeds and also not within
seedlings, besides the root tips, whereas an arbuscular mycorrhizal Glomus species was seed-borne and
present throughout most of the seedling. A close association between T. viride and a Glomus species associated with O.