Discover the Green in Your World and Get to Its Roots (Science Rendezvous)

Below is information about preparations for the Science Rendezvous (Discover the Green in Your World and Get to its Roots) event (Greenhouse: 09 May 2009)

Root Growth

The objective is to reveal the remarkable contribution of root growth to the overall growth of a plant.

Glass tube setup The method was to fill large bore glass tubes (3.5 cm or 4.75 cm inner diameter, 1.2 meters long) with a standard potting soil mix (without added sand to minimize abrasion of the glass tubes). One end of the tube was covered with a cotton gauze and placed in a pot of soil. The soil was wetted, then sown with tomato or bean seeds, or with a transplant (a Penta (?) sp., kept in the greenhouse; it should be flowering by the time of the event; the tube is covered with aluminum foil to minimize light avoidance by the developing roots).

The glass tubes were mounted in a research lab at 25 degrees Celsius

Once the seeds had germinated (within four days), a fluorescent light was positioned close to the top of the tube. The fluorescence tubes were T8, with a colour temperature of 6500K (that is, a strong blue color to maximize plant growth). The irradiance (50 µmol m-2 sec-1) is about 2.5% the intensity of direct sunlight.

Here is a more detailed description of the technique and possible experiments:
[pdf] (30 MB)

Here are some beautiful images of the seedlings (courtesy Milissa Elliott)(click on photo for a higher resolution tif)(day 6)

Tomato seedlings --day 6
bean seedlings --cotyledons emerging


And even more beautiful images of the seedlings (courtesy Milissa Elliott)(click on photo for a higher resolution tif)(day 9)
Tomato seedlings --day 9


bean seedlings --primary leaves emerging


Plant Dissections

The objective is to give younger children the opportunity to explore the root system of plants and give them a sense of the plant world UnderGround.

Plant Dissection Children were asked to select among a variety of potted plants (lilies and geraniums). With selection in hand, they removed the plant from the pot, and teased away the dirt surrounding the root system with their hands. When finished, they took their plants to a dissecting microscope, to explore the difference between the root system and the aboveground parts of the plants. Fun was had by all.


Pollen Growth

The objective is to reveal the remarkable properties of cellular growth during plant pollination.

Microscope Children (and adults!) could observe the rapid growth of individual pollen in wet mounts under a microscope with a video/monitor hook-up.