Prediction

Seed treatment

What we know

We know that if the seeds are planted in a suitable medium and provided with ideal germinating conditions of water, oxygen and warmth they should show sprouts within 6-14 days.

We also know that the seedlings within the seed coat are in a dormant state and are highly resistant to damage from the impact of temporary conditions which are unfavourable for germination.

A seed's resistance to damage from exposure to environmental extremes depends upon the intensity of the extreme condition and the duration of the exposure.

Seed treatment

The tomato seeds used in this project, 9478 F1 Hybrid, have been supplied by Heinz Canada. Your class will receive approximately 60 tomato seeds - 30 seeds in each of the following two groups:

Control Group: Tomato seeds especially cultivated for food production on Earth. These are ordinary tomato crop seeds used for Earth-based tomato production.
Non-control Group: The treatment group of Tomatosphere seeds was taken into space to the International Space Station (ISS) by CSA Astronaut, Julie Payette, on Mission STS-127, aboard Space Shuttle Endeavour from July 15th to 31st, 2009.

The “treatment” to which the seeds were exposed included a number of elements during their two-month stay on the ISS. These were: 1) an increase in pressure on the Shuttle flight to the ISS, 2) the weightless environment while on board the ISS, 3) a slight increase in the amount of radiation which all living things experience outside of the Earth’s protective atmosphere and 4) on return to the Earth’s atmosphere, the seeds were again exposed to increased pressure.

The non-control group of Tomatosphere seeds was subjected to a simulation of the Martian surface environment for a period of one week. This was carried out at the Kennedy Space Center in Florida. The temperature in the simulator was -50°C, with a 95% concentration of CO2 and an increased intensity of ultraviolet light, similar to that found on the surface of Mars. The pressure in the simulator was very low - 0.6 kilopascals (kPa), compared to Earth which averages 101.32 kPa.

How will our seeds react to exposure to these conditions?

The size and hardiness of tomato seeds make them important candidates for the Mars life support system for the mission team. The discovery that tomato seeds are damaged by exposure to conditions such as those found on board the International Space Station, in a greenhouse on the Moon, or a vehicle proceeding from Earth to Mars or by exposure to the Martian environment, would be a fatal blow to this aspect of the mission plan. What predictions can we make about the results of the Tomatosphere experiment?

Prediction	Seeds that have been to the International Space Station Choose ONE of the situations in the left-hand column. Explain why you made that prediction. Add any questions that your prediction raises that you want to try and answer.
No effect: Seeds will germinate the same as the control group.
All seeds will survive but some will be slower to germinate than the control group
Some seeds will NOT survive but germination will be at the same rate as the control group
Some seeds will NOT survive AND will be slower to germinate than the control group
Most seeds will NOT survive and few will germinate compared to the control group
All of the seeds will not survive; there will be no germination of the seeds that were in space and on the International Space Station for two months.
Other

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