Brassica Rapa Experiment

Abstract

The plant Brassica rapa is a fast plant most commonly known as the field mustard. The plant itself particularly well known for its extremely fast rate of growth, making it easy to breed and cross pollinate several generations. Due to its ability of rapid growth it has become a favorite for scientist to test the theories of inheritance on. In our case we tested to see if we could affect the overall hairiness of different generations. F1 seed was ordered, germinated and cross-pollinated until germination of the next off spring of plants were also done. We hypothesized that the presence of hairiness is inherited as a dominant trait and follows basic inheritance laws. The experiments were performed in quads, with the different quads
To do this we first found and then labeled a styrofoam holder with four groups each containing four separate places to grow the plants. Once labeled we placed a single wick into each point where a Fast Plant would be growing (16 in total) and proceeded to fill these spaces up with two various kinds of dirt to ensure a better growing environment. Next hairy and hairless seeds were obtained from our instructor and three seeds were placed into section along with two pellets of plant food. After this was done we watered our container with seeds and waited for the plants to grow before we could go further with the lab. They were placed into a large tray and placed under white light in a special plant growing chamber where a steady amount of light was applied, air circulation monitored, and where the trays were filled with 1-2 inches of water twice a week. After several class periods, and we were certain that they had grown to a sufficient size we noted the tank number that our plants grew up in and used a magnifying glass to count the hairs on the edge of the first true leaf known as trichomes of each and every individuals plant that grew. We then put a piece of tape near each plant and recorded the number of hairs for each one found in P1 (hairy), P2 (hairless), F1, and F2. After many days had passed and our Fast Plants had begun to flower we choose the F2 plants with the hairiness in the top 10% of the population of F2 for our group. We then separated these plants from the rest of the population and cross pollinated the F2s with each other. We did this by using a rod with a bee attached to the ned of it by gently touching the anthers of one flower on Plant 1 with the tip of the rod to collect the pollen grain and delivered the pollen grain to the stigma of a flower on Plant 2 in the same pot. Similarly, we gently touched the anthers of one flower on Plant 2 with the tip