Plant Choice Results

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Grow box seeded with both radish and lettuce seeds (Fig 1.). Initial sprouting of radish seeds (Fig 2.) and lettuce seeds (Fig 3.). Growth at 11-day post seeding for both radish (Fig 4.) and lettuce (Fig 5.). Growth of radish and lettuce seeds at 28-days post initial seeding.

Plant Choice Discussion

As expected from seed growth information provided with the seeds, and from online research, the radish seeds not only sprouted first but they were close to maturity by the 21-day timepoint. Each seed observed the same growth pattern with all growth being initially observed at 5 days +/- 12 hours.

The lettuce was initially slower to sprout (8 days approx for the first observed growth) and was not consistent across those that were planted (some seeds initially took 24-96 hours longer to sprout). However, by day 21 there seemed to be no clear difference in sizes of lettuces and an even growth was observed across that section of the grow box.

Whilst both radish and lettuce seeds produced post 21-day growth (Fig 6.) that could be used throughout this project to easily quantify potential growth-inhibiting/promoting factors in further testing, radish seeds were chosen for further testing due to their efficient and replicable growth patterns observed during this test.

Biofrag 1.0 Seed Growth Ability Results

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Position of Biofrag in glass jar allowing for unimpeded sunlight (Fig 7.) and with soil filled around it and up to its apex (Fig 8). No growth was observed 21-days post seeding (Fig 9).

Biofrag 1.0 Seed Growth Ability Discussion

The lack of any growth may have been due to several reasons. The compact nature of the sponge and lack of room may not have been conducive to seed germination. The obvious reason may be just that the removal of growth medium (soil) from around the seed did not allow for germination and may be a deciding factor upon choice of Biofrag design going forwards. Although the choice of housing was different from initial growth experiments, it was though the material choice (glass) would not negatively influence assay outcome. However, the increased light and potentially differential temperature from that within the Perspex contained grow box may have been contributing factors to null growth observed. It was decided to repeat the assay using the exact criteria previously used in the initial growth studies.

Alternate Biofrag 1.0 Seed Growth Ability Results

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Biofrag replanted within the grow box (Fig 10.) and growth of seeds through both the outer Biofrag (Fig 11) and inner Biofrag (Fig 12).

Alternate Biofrag 1.0 Seed Growth Ability Discussion

Growth was observed from two seeds overall, but the growth rate was much slower than expected with observable growth not until approx 7-days post seeding. Whilst observable growth proceeded there was a halt after approximately a further 7-days after which there was no increase in plant size. However, plant health remained until end of 21-day timeframe, and though no additional growth was observed, the plant maintained colour and rigidity comparable with live plants.
From these results, it was deemed an alternative Biofrag design was needed and possibly an alternative to the dense sponge used at this time.

Biofrag 2.0 Seed Growth Ability Testing Results

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The 3D printed Biofrag 2.0 model (Fig 13) and the hose adaption for filling (Fig 14 and Fig 15). Buried Biofrag 2.0 with portal facing upwards for unimpeded growth (Fig 16) and observed growth at days 11 and 21 (Fig 17 and Fig 18).

Biofrag 2.0 Seed Growth Ability Discussion

Although both Biofrags were seeded 2-days apart, initial growth was much faster in one compared to the other. Whilst one Biofrag produced growth like the control seeds around it (sprouting 5-days +/- 12hrs post planting) the other did not have observable growth for an additional 4-days approximately (post-seeding) though the controls were as expected. In grow box 1, growth between the Biofrag seed and the control seeds followed a very similar pattern with no clear difference between any of the plants. Although slower to initiate, the seed growth in grow box 2, within the Biofrag, continued at the same rate of growth as all other controls and the other Biofrag.

Seed Growth in Varying Perchlorate Concentration Results

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The controls (0% Perchlorate) had similar growth in both the RODI (Left) and DMM (Right) tubes (Fig 19). Both the RODI (Left) and DMM (Right) 0.25% concentrations produced growth with slightly more observed in the DMM (Fig 20). Neither the 0.5% or 1% Perchlorate concentrations produced growth in either the RODI or DMM (Fig 21 and Fig 22 respectively).

Seed Growth in Varying Perchlorate Concentrations Discussion

From the growth observed, it is clear there is little difference in growing these seeds in either RODI or DMM. Any small differences seen may be down to natural seed composition or growth patterns. The lowest perchlorate concentration (0.25%) allowed growth but at a slower rate than the controls and all concentrations above this (0.5% and 1.0%) did not provide an environment suitable for seed growth. These results highlight the need for remediation of Martian soil, as introducing plant life, even as a potential oxygen source, would require soil perchlorate concentrations to be much lower than those currently experienced.