As the first step for the evolution of our living on Mars, the germination and growth of Lotus japonicus sown on the Martian regolith simulant containing basaltic ash emitted from Miyake volcano were investigated. The Martian regolith simulant strongly inhibited the germination and growth of L.japonicus. However, the inhibition was weakened by adding sphagnum moss into the Martian regolith simulant, though sphagnum moss itself somewhat suppressed the germination and growth of them. These results suggest that too high pH of the Martian regolith simulant was neutralized by acid sphagnum moss and the suppressing ability of sphagnum moss is mitigated with the Martian regolith simulant. The productive function related to symbiosis in L. japonicus infected with Mesorhizobium loti of signaling substances, flavonoids, was also analyzed. The productive ability of flavonoids including some signal compounds inducing nodulation was not much affected by addition of sphagnum moss to the Martian regolith simulant. This might be a indication of successful nodulation of the leguminous plant of Martian regolith.

Key words: Lotus japonicus, Martian agriculture, Martian regolith simulant, Space agriculture, Sphagnum moss